® 268XA Data Acquisition System/Data Logging System Service Manual PN 1883791 November 2002 © 2002 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies.
Limited Warranty and Limitation of Liability Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is one year and begins on the date of shipment. Parts, product repairs and services are warranted for 90 days.
WCaution This is an IEC safety Class 1 product. Before using, the ground wire in the line cord or rear panel binding post must be connect to an earth ground for safety. Interference Information This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the manufacturer’s instructions, may cause interference to radio and television reception.
SYMBOLS MARKED ON EQUIPMENT: WARNING Risk of electric shock. Ground (earth) terminal. Protective ground (earth) terminal. Must be connected to safety earth ground when the power cord is used. Attention. Refer to the manual. This symbol indicates that information about usage of a feature is contained in the manual. This symbol appears on the Universal Input Module and in the following two places on the device rear panel: 1. Ground Binding Post (to the left of the line power connector). 2.
XWWARNING To avoid possible electric shock or damage to the device: • Read manual before operating. • Do not position device so that air flow through side vents is restricted. • Do not use in a manner not specified in this manual or safety protection may be impaired. • Disconnect power cord and ALL other inputs before replacing a fuse. • Position the device where power cord can be disconnected. • Do not exceed maximum voltages.
Table of Contents Chapter 1 Title Page Introduction and Specifications........................................................ 1-1 Introduction ....................................................................................................... Block Diagrams ................................................................................................. Specifications ....................................................................................................
268XA Service Manual 2 Theory of Operation........................................................................... 2-1 Introduction ....................................................................................................... Main Power Supply....................................................................................... Secondary Supplies ....................................................................................... Out-Guard Overview.........................................
Contents (continued) Open Thermocouple Detect Circuitry....................................................... A4 Analog Input PCA Circuit Description ................................................... A31 A/D Power Supply Circuit Description................................................. Controller/System Power (Outguard) to A3 A/D Converter (Inguard) Communications ........................................................................................... Special Codes ................................
268XA Service Manual Trigger Input Tests........................................................................................ RS-232 Trigger Input Test ........................................................................ Fluke DAQ Trigger Input Test ................................................................. Trigger Output Tests ..................................................................................... RS-232 Trigger Output Test ......................................................
Contents (continued) Diagnostic Tool dio....................................................................................... Diagnostic Tool rELAy................................................................................. Diagnostic Tool idS....................................................................................... Diagnostic Tool conF.................................................................................... Diagnostic Display Test ............................................
268XA Service Manual vi
List of Tables Table 1-1. 1-2. 1-3. 1-4. 1-5. 1-6. 1-7. 1-8. 1-9. 1-10. 1-11. 1-12. 1-13. 1-14. 1-15. 1-16. 1-17. 1-18. 1-19. 1-20. 1-21. 1-22. 1-23. 1-24. 1-25. 1-26. 1-27. 1-28. 1-29. 1-30. 1-31. 1-32. 1-33. 1-35. 1-36. Title 268XA General Specifications .............................................................................. 268X Real-Time Clock and Calendar.................................................................... Trigger In Specification ...............................................
268XA Service Manual 1-37. 1-38. 1-39. 1-40. 2-1. 2-2. 2-3. 2-4. 2-5. 2-6. 2-7. 2-8. 2-9. 2-10. 2-11. 2-12. 2-13. 2-14. 2-15. 2-16. 2-17. 2-18. 3-1. 4-1. 5-1. 5-2. 5-3. 5-4. 5-5. 5-6. 5-7. 6-1. 6-2. 6-3. 6-4. 6-5. 6-6. 6-7. 6-8. 6-9. 6-10. 6-11. 6-12. 6-13. DIGITAL I/O Specification................................................................................... Totalizer Specification ...........................................................................................
List of Figures Figure 1-1. 1-2. 2-1. 2-2. 2-3. 2-4. 2-5. 2-6. 2-7. 2-8. 2-9. 2-10. 2-11. 2-12. 2-13. 2-14. 3-1. 3-2. 4-1. 4-2. 4-3. 4-4. 4-5. 5-1. 5-2. 5-3. 5-4. 6-1. 6-2. 7-1. 7-2. 7-3. 7-4. 7-5. 7-6. Title 2680A/2685A Device ............................................................................................ 268XA Chassis ...................................................................................................... Communication Control System............................................
268XA Service Manual 8-1. 8-2. 8-3. 8-4. 8-5. 8-6. 8-7. 8-8. 8-9. 8-10. 8-11. 8-12. Backplane PCA...................................................................................................... Controller/System Power PCA .............................................................................. Digital I/O PCA ..................................................................................................... Backplane Extender PCA ..............................................................
Chapter 1 Introduction and Specifications Title Introduction ....................................................................................................... Block Diagrams ................................................................................................. Specifications .................................................................................................... 2680A/2686A Combined Specifications.......................................................
268XA Service Manual 1-2
Introduction and Specifications Introduction 1 Introduction The 268XA Service Manual supports the performance testing, calibration, servicing, and maintenance of the 2680A Data Acquisition System (DAS), the 2686A Data Logging System (DLS) and modules. See Figure 1-1 for a view of the 268XA. The 2686A comes with a removable PC Card (PCMCIA) for stand-alone storage operation. This socket accepts ATA memory cards up to 2 GB in size. Each 268XA device can hold from 1 to 6 analog modules.
268XA Service Manual 2680 SER IES DAQ SYSTEM REVI EW LAST MAX REM MIN AUTO SCAN MON SET FUNC Mx+B ALAR M C F RO mV AC DC x1Mk Hz F LIMI T HI 1 2 LO OFF PRN CH CAL EXT TR alg46f.eps Figure 1-1.
Introduction and Specifications Block Diagrams 1 Block Diagrams A/D Input Card (one of six) Removable 20 channel input port with built in temp sensor Power Filter and A/D circuits Switch Matrices (FET or Relay) Ctrl Power Daughter Card Data Microprocessor Isolated Power Data M o t h e r b o a r d / C o n t r o l l e r Optoisolators Ctrl A/D #2 A/D #3 A/D #4 A/D #5 DIO or A/D #6 External Trig in External Trig out Controller RAM FLASH Real Time clock TCP/IP Network Ethernet RS232 (cal/te
268XA Service Manual Digital I/O Output Card Removable Connector Card Isolated Power Digital I/O (20) and Totalizer (1) Ctrl Relay Contact (8 pr) Ctrl Power Daughter Card Data Microprocessor and drivers Data Optoisolators M o t h e r b o a r d / C o n t r o l l e r Ctrl A/D #1 A/D #2 A/D #3 A/D #4 A/D #5 External Trig in Controller RAM FLASH Real Time clock Display/ Keypad Tcp/IP Network Ethernet RS232 (cal/test) RS232 A/C and Battery Supply Circuits DC Power Bus PCMCIA Type II Memory
Introduction and Specifications Specifications 1 Specifications Specifications are divided into four sections. The first section contains the specifications that apply to both the 2680A and 2686A devices. The second section contains specifications that apply only to the Precision A/D Input (PAI) module. The third section contains specifications that apply only to the Fast A/D Input (FAI) module. The last section contains information only for the digital I/O relay and the totalizer (DIO) module.
268XA Service Manual 2680A/2686A General Specifications Table 1-1 provides the general specifications for the 2680A and 2686A devices. Table 1-1. 268XA General Specifications Specification 1-8 Characteristic Input Channel Capacity Maximum of 120 channels (Precision or Fast Analog Input) per chassis Optional DIO 20 digital input and outputs channels, 8 double pole-single throw relay channels, a totalizer input, and a totalizer enable input. Computed Channels 60 Size 473 mm (18.
Introduction and Specifications Real-Time Clock and Calendar 1 Real-Time Clock and Calendar The next table provides a summary of the battery powered real-time clock and calendar. Table 1-2. 268X Real-Time Clock and Calendar Specification Characteristic Accuracy 1 minute per month for 0 °C to 50 °C range Battery Life >5 unpowered device years for 20 °C to 28 °C (68 °F to 82.4 °F). Trigger In Specifications The following table provides a summary of the Trigger In specifications.
8XA Service Manual Master Alarm Output Specification The following specifications cover the Master Alarm output. The Master Alarm output is located on the rear panel connector, terminals Master Alarm, and Signal GND. Table 1-5. Master Alarm Output Specification Specification Characteristic Output Voltage - TTL Logical Zero 0.8 V maximum for an Iout of -1.0 mA (1 LSTTL load) Output Voltage - TTL Logical One 3.8 V minimum for an Iout of 0.05 mA (1 LSTTL load) Output Voltage - Non-TTL Load Zero 1.
Introduction and Specifications Precision Analog Input (PAI) A/D Specifications 1 Precision Analog Input (PAI) A/D Specifications This section includes specifications specific to the PAI A/D instrument by measurement function. Specifications PAI A/D DC Voltage Measurement The following tables provide PAI A/D specifications for the dc voltage measurement function. Table 1-7.
268XA Service Manual Table 1-8. PAI A/D DC Voltage Range and Resolution Specifications Resolution Range Slow Fast 90 mV 0.3 µV 1 µV 300 mV 1 µV 3 µV 3V 10 µV 30 µV 30 V 100 µV 300 µV 150/300 V 1 mV 3 mV Note 300 V range applies to channels 1 and 11 only. Table 1-9. PAI A/D DC Voltage Accuracy Specifications Accuracy, 3σ + (% input + V) 18 °C to 28 °C Range 90 Day Slow 1 Year Fast Slow 1 Year Fast Slow Fast 90 mV .01%+7 µV .01%+17 µV .013%+8 µV .013%+18 µV .042%+18.2 µV .
Introduction and Specifications Precision Analog Input (PAI) A/D Specifications 1 PAI A/D AC Voltage Measurement Specifications The following tables provide PAI A/D specifications for the ac voltage measurement function. Table 1-10. PAI A/D AC Voltage General Specifications Specification Characteristic Input Impedance 1 MΩ in parallel with 100 pF Maximum Crest Factor 3.0 Maximum 2.
268XA Service Manual Table 1-12. PAI A/D AC Voltage Accuracy Specifications 1 Year Accuracy + (%input + V) [1] Range Frequency 18 °C to 28 °C Slow 300 mV 3V 30 V 150/300 V Fast Slow Fast 20 to 50 Hz 3%+.25 mV 6%+.5 mV 3.5%+.25 mV 7%+.5 mV 50 to 150 Hz 0.4%+.25 mV 1%+.5 mV 0.5%+.25 mV 1.5%+.5 mV 150 Hz to 10 kHz 0.3%+.25 mV 1%+.5 mV 0.4%+.25 mV 1.5%+.5 mV 10 kHz to 20 kHz 0.4%+.25 mV 1%+.5 mV 0.7%+.25 mV 1.5%+.5 mV 20 kHz to 50 kHz 2%+.3 mV 3%+.5 mV 3%+.3 mV 4%+.
Introduction and Specifications Precision Analog Input (PAI) A/D Specifications 1 PAI A/D 4-Wire Resistance Measurement Specifications The following tables provide PAI A/D specifications for the 4-wire resistance measurement function. The 4-wire measurements use 2 input channels a decade apart, e.g., channels 4 and 14. Table 1-13. PAI A/D 4-Wire Resistance Temperature Coefficient Specification Characteristic Temperature Coefficient Add 1/10th the 90 day specification per °C above 28 °C or below 18 °C.
268XA Service Manual PAI A/D 2-Wire Resistance Measurement Specifications The PAI A/D specifications for the two-wire resistance measurement function is based on the four-wire resistance measurement specification (above) except you add a nominal 5 Ω (10 Ω maximum) positive offset. This value varies for each channel and with temperature (nominal +1%/ºC).
Introduction and Specifications Precision Analog Input (PAI) A/D Specifications 1 PAI A/D Thermocouple per ITS-1990 Measurement Specifications The following tables provide PAI A/D specifications for the thermocouple measurement function per ITS-1990. Table 1-18. PAI A/D Thermocouple General Specifications Specification Characteristic Input Impedance 100 MΩ minimum in parallel with 300 pF Open Thermocouple Detect Operates by injecting a small ac signal into the input after each measurement.
268XA Service Manual Table 1-19. PAI A/D Thermocouple Specifications Accuracy + °C Thermocouple Resolution ITS90 °C Type B C E J K L 1-18 Temperature °C 18 °C to 28 °C 90 Day -10 °C to 60 °C 1 Year Slow Slow 1 Year Fast Slow Fast 600 to 900 0.2 1.20 1.40 3.10 1.50 3.20 900 to 1200 0.2 0.90 1.00 2.20 1.20 2.40 1200 to 1820 0.1 0.75 1.00 1.90 1.30 2.20 0 to 150 0.2 0.80 0.90 1.60 1.00 1.70 150 to 650 0.1 0.65 0.75 1.40 1.00 1.50 650 to 1000 .05 0.
Introduction and Specifications Precision Analog Input (PAI) A/D Specifications 1 Table 1-19. PAI A/D Thermocouple Specifications (cont.) Accuracy + °C Thermocouple Resolution ITS90 °C Type N R S T U Temperature °C 18 °C to 28 °C 90 Day -10 °C to 60 °C 1 Year Slow Slow 1 Year Fast Slow Fast -100 to –25 .05 0.65 0.75 1.20 0.80 1.30 -25 to 120 .05 0.55 0.60 1.00 0.70 1.10 120 to 1000 .04 0.45 0.60 0.90 1.00 1.20 1000 to 1300 .03 0.55 0.75 1.00 1.20 1.
268XA Service Manual PAI A/D Frequency Measurement Specifications The following tables provide PAI A/D specifications for the frequency measurement function. Table 1-20. PAI A/D Frequency Accuracy Specifications Frequency Measurement Accuracy, 1 Year, -10 °C to 60 °C Range Resolution Slow Accuracy + (% input + Hz) Fast Slow Fast 15 Hz to 900 Hz 0.01 Hz 0.1 Hz 0.05%+0.02 Hz 0.05%+0.2 Hz 900 Hz to 9 kHz 0.1 Hz 1 Hz 0.05%+0.1 Hz 0.05%+1 Hz 9 kHz to 90 kHz 1 Hz 10 Hz 0.05%+1 Hz 0.
Introduction and Specifications Fast Analog Input (FAI) A/D Specifications 1 Fast Analog Input (FAI) A/D Specifications This section includes specifications specific to the FAI A/D instrument by measurement function. FAI A/D DC Voltage Measurement Specifications The following tables provide FAI A/D specifications for the dc voltage measurement function. Table 1-22.
268XA Service Manual Table 1-24. FAI A/D DC Voltage Accuracy Specifications Accuracy, 3σ + (% input + V) 18 °C to 28 °C Range 90 Day Slow -10 °C to 60 °C 1 Year Fast Slow 1 Year Fast Slow Fast 90 mV .01%+20 µV .01%+50 µV .013%+23 µV .013%+50 µV .042%+52 µV .042%+130 µV 300 mV .01%+40 µV .01%+90 µV .013%+49 µV .013%+93 µV .042%+104 µV .042%+234 µV 3V .01%+.3 mV .01%+.6 mV .013%+.38 mV .013%+.64 mV .042%+.78 mV .042%+1.56 mV 30 V .01%+4 mV .02%+8 mV .013%+4.9 mV .026%+9.
Introduction and Specifications Fast Analog Input (FAI) A/D Specifications 1 Table 1-26. FAI A/D AC Voltage Range and Resolution Specifications Resolution Range Minimum Input for Slow Rate Accuracy Fast Full Scale +30,000 +3,000 300 mV 10 µV 100 µV 20 mV 3V 100 µV 1 mV 200 mV 30 V 1 mV 10 mV 2V Table 1-27.
268XA Service Manual FAI A/D 4-Wire Resistance Measurement Specifications The following tables provide FAI A/D specifications for the 4-wire resistance measurement function. The 4-wire measurements use 2 input channels a decade apart, e.g., channels 4 and 14. Table 1-28. FAI A/D 4-Wire Resistance Temperature Coefficient Specification Characteristic Temperature Coefficient Add 1/10th the 90 day specification per °C above 28 °C or below 18 °C.
Introduction and Specifications Fast Analog Input (FAI) A/D Specifications 1 FAI A/D 2-Wire Resistance Measurement Specifications The FAI A/D specifications for the two-wire resistance measurement function is based on the four-wire resistance measurement specification (above) except you add a 700 to 1000 Ω positive offset. This value varies for each channel and temperature gradient (nominal +1%/ºC).
268XA Service Manual FAI A/D Thermocouple per ITS-1990 Measurement Specifications The following tables provide FAI A/D specifications for the thermocouple measurement function per ITS-1990. Table 1-33. FAI A/D Thermocouple General Specifications Specification Characteristic Input Impedance 100 MΩ minimum in parallel with 300 pF Open Thermocouple Detect Operates by injecting a small ac signal into the input after each measurement.
Introduction and Specifications Fast Analog Input (FAI) A/D Specifications 1 Table 1-34. FAI A/D Thermocouple Specifications (cont.) Accuracy + °C Thermocouple Resolution ITS90 °C Type J K L N R S T U Temperature °C 18 °C to 28 °C 90 Day Slow -10 °C to 60 °C 1 Year Slow 1 Year Fast Slow Fast -100 to 80 .3 0.80 0.90 1.60 0.90 1.70 80 to 230 .2 0.70 0.80 1.40 0.90 1.50 230 to 760 .2 0.70 0.80 1.30 1.00 1.50 -100 to -25 .4 1.00 1.10 2.00 1.20 2.10 -25 to 120 .
268XA Service Manual Table 1-34. FAI A/D Thermocouple Specifications (cont.) Thermistor Accuracy + °C 90 Day Temp °C -40 to 150 Range* 1 Year Slow 100 to 100 mΩ Slow 0.4 18 to 23 °C 0.51 Steinhart – Hart Equation: 1/(T Kelvin) = A + B*(ln Ω) + C*(ln Ω) o 3 Default constants are supplied only for a YSI (type 004) 2,252 Ω thermistor, you can enter constants for other thermistors. The ranges of thermistor constants are as follows: A 1.0E-4 to 1.0E-2, B 1.0E-5 to 1.0E-3, and C 1.0E-8 to 1.0E-6.
Introduction and Specifications Digital Input/Output Module 1 Digital Input/Output Module The following specifications apply to the DIO Module. The module contains digital open collector outputs, relay contacts, digital inputs, and totalizer. XWWarning The DIO module is rated as a CAT I device. Digital Input/Output Specifications Table specifications provides a summary of the Digital I/O specifications for the 10 Digital I/O lines (0 to 19).
268XA Service Manual Totalizer Input Specifications The following table provides a summary of the Totalizer Input specifications. The Totalizer Input is located on the Output Module connector, terminals TOI and GND. The totalizer will be able to increment or decrement depending on the input on a separate digital input channel. Table 1-38.
Introduction and Specifications Options and Accessories 1 Options and Accessories Table 1-40 summarizes the available Models, Options and Accessories. Table 1-40.
268XA Service Manual 1-32
Chapter 2 Theory of Operation Title Introduction ....................................................................................................... Main Power Supply....................................................................................... Secondary Supplies ....................................................................................... Out-Guard Overview..................................................................................... Microprocessor ..........................
268XA Service Manual Input Protection......................................................................................... Input Signal Conditioning......................................................................... Function Relays ........................................................................................ Channel Selection Circuitry...................................................................... DC Volts and Thermocouples Measurement Circuitry.............................
Theory of Operation Introduction 2 Introduction This chapter is intended to provide a detailed description and analysis, where appropriate, of the printed circuit board assemblies (PCAs) used in the 268XA. Figure 2-1 below is an overall block diagram of the communication control system. Note that the blocks labeled "Module #n" can be any valid module type, either FAI, PAI or DIO. The hardware system functionality is independent of the module type. PCMCIA Slot 2686A only Transreceivers PCMCIA v2.
268XA Service Manual Power Switch Input Recepticle Grn/Yel Fuse P9 Red Brn Orn Blu Blk Wht Twisted Pair Controller Board 7 12 Mains XFMR 6 Twisted Pair 1 alg112f.eps Figure 2-2. 268XA Main Supply Circuit The 4004 PCA is the main board in the 268XA chassis. It contains the main switching power supply and various secondary power supplies, as well as all of the out-guard digital control circuitry, guard-crossing interface and host computer interface, both 10/100 Base T Ethernet and RS-232.
Theory of Operation Introduction 2 Main Power Supply The power supply circuitry is contained on page 6 of the 2680-1004 schematic. The main supply consists of 2 switching regulators, U301 and U303. U301 takes either a 9 V to 42 V dc source from P6 pins 1 and 2 or a 10:1 stepped down 50/60 Hz 95 V to 265 V ac line voltage from P9 pins 3 and 4 as an input.
268XA Service Manual Microprocessor The processor used in the 268XA (U6) is a Motorola MPC855T, see page 2 of the 1004 schematic. Its architecture is very similar to the 683xx series of embedded communications controllers that have been used on many product lines, including NetDAQ and 55xx series calibrators, except that instead of a 16 bit 68000 processor core with no instruction or data cache, the MPC855T has a 32 bit power PC core with 4 Kbytes of both L1 instruction and data cache.
Theory of Operation Introduction 2 FPGA The gate array (U25) in the 268XA is an Altera ACEX series EP1K100QC208-1. It is on page 5 of the 1004 schematic. It has 48Kbits of embedded dual port RAM configurable in 12 blocks of various width/depth combinations, as well as approximately 100K gates. This design uses about 55 % of the logic cells, and about 25 % of the memory bits, spread out over all 12 blocks, and has a maximum clock frequency of 57.4 MHz. The core runs off of a 2.
268XA ewr4 ewr5 ewr2 ewr3 ewr1 ewr1 peup_ck peup_ck* grd_ck5 grd_ck5* grd_ck4 grd_ck4* grd_ck3 grd_ck3* grd_ck2 grd_ck2* grd_ck1 grd_ck1* grd_ck0 grd_ck0* rx5 tx5 rx4 tx4 rx3 tx3 rx2 tx2 rx1 tx1 rx0 tx0 Service Manual Rx FIFO Tx FIFO Rx FIFO Tx FIFO Rx FIFO Tx FIFO Rx FIFO Tx FIFO Rx FIFO Tx FIFO Rx FIFO Tx FIFO URT URT URT URT URT URT Clock Generator Keypad key_ck Guard xing keypad_irq* Trig Out Trig CPU Trig In Trigger In/Out Entity eyedk data addr ce* oe* we* r_w bus_error se
Theory of Operation Introduction 2 This particular series of devices is presently available in 2 other sizes, 8 MB and 16 MB, provisions have been made in this design for using those devices if necessary, with minimal required rework. U20 is programmed and powered from Vcc, there is no additional 12 V programming voltage required for Strataflash devices. Support is provided, in the form of bus transceivers and daughter card connector (U4, 5, 10, 28, 29, and P4), for a single PCMCIA slot.
268XA Service Manual The overvoltage protection for these 3 signals consists of a 49.9 Ω series resistor, a dual diode clamp and a 6 V Zener diode. This scheme will protect the fpga and microprocessor for applied voltages up to +/- 30 V dc. The trigger input buffer is a CMOS Schmidt trigger. The trigger out and master alarm out are driven by NDS351 NMOS FETs with 2 kΩ pull-up resistors to the +5 V rail. PCMCIA Interface PCA (2686A-4041) The PCMCIA interface board mainly consists of a type II 3.
Theory of Operation Module Power Supply PCA (268XA-4031) 2 Display Interface The display controller interface on the backplane consists of a tri-stateable levelshifter/buffer, some decoupling capacitors, and the display ribbon cable connector (P8). The levelshifters (U1, 2, 3) need to be tri-stateable because, when the microprocessor is talking to the calibration EEPROMs, the display should not receive those transmissions.
268XA Service Manual Microcontroller A Texas Instrument MSP430P337A mixed signal microcontroller is the heart of the DIO PCA. The microcontroller, U4, features bi-directional digital ports, a built in UART and internal timers for controlling operation. A quartz crystal operating at 32.8 kHz provides the main clock signal for the microcontroller. This signal is internally multiplied to 3.
Theory of Operation Digital Input/Output PCA 2 Digital Input Buffers Since the 20 Digital Input Buffers are identical in design, only components used for Digital Input 0 are referenced in this description. If the Digital Output Driver (U13 Pin 13) is “off”, the input to the Digital Input Buffer is determined by the voltage level at P6 Pin A1. If the Digital Output Driver is “on”, the input of the Digital Input Buffer is the voltage at the output of the Digital Output Driver.
268XA Service Manual Totalizer Input The Totalizer Input circuit consists of Input Protection, a Digital Input Buffer circuit, and a Totalizer Debouncing circuit. The Digital Input Buffer for the Totalizer is protected from electrostatic discharge (ESD) damage by R31 and C48. Refer to the detailed description of the Digital Input Buffer circuit for more information. U1 and U18 provide input buffering for the Totalizer.
Theory of Operation A/D Theory of Operations 2 Analog Measurement Processor The Analog Measurement Processor (A3U30) provides input signal conditioning, ranging, and frequency measurement. This custom integrated circuit is controlled by the inguard A/D Microprocessor (A3U5). The A/D Microprocessor communicates with the main Controller/System Power PCA over a serial interface. Isolation is achieved through the A/D power supply daughter card with a unique dc to dc converter.
268XA Service Manual Open Thermocouple Check Under control of the inguard microprocessor, the open thermocouple check circuit applies a small ac signal to a thermocouple input before each measurement. If an excessive resistance is encountered, an open thermocouple input condition is reported.
Theory of Operation A/D Theory of Operations 2 A4 Analog Input EMI Filters Ch1 to 10 Scanner Relays Ch11 to 20 Scanner Relays Relay Drivers Treeing Relays Ohms Current Source Voltage Input Input Protection Signal Conditioning Selectable Gains DC Buffer Amplifier +3.45V dc References x1 x10 x4.021 x32.168 A/D Converter BR4 BR3 BR2 BR1 FPGA RAM Serial Bus A/D Microprocessor Latches Flash Vdd=+5.2V dc Vss=-5.2V dc Vddr=+5.6V dc Serial Digital Output (Guard Crossing) Reg Vcc=+5.
268XA Service Manual Stallion Chip The Stallion IC (A3U30) is a Fluke-designed 100-pin CMOS device that performs the following functions under control of the A/D microprocessor (A3U5): • Input signal routing • Input signal conditioning • A/D buffer amplifier range switching • Frequency measurements • Active filtering of ac voltage measurements The Stallion IC design is taken from the NetDAQ design and contains the A/D conversion function using a multi-slope technique.
Theory of Operation A/D Theory of Operations 2 Channel Selection Circuitry Channel selection is done using reed relays on the PAI and by optically coupled solid-state relay on the FAI. Channel selection is done by a set of 24 relays organized in a tree structure. Relays A3K1 through K20 select the specific channel 1-20.
268XA Service Manual Table 2-4. Measurement Matrix for DC Volts DC Volt Range Gain of DC Buffer Amplifier Full-Scale Output of Stallion Input to Stallion Full-Scale DC Volts Input to Multislope A/D Buffer Range Control Signal 90 mV Direct 90 mV 32.168 3V BR1 300 mV Direct 300 mV 10.00 3V BR3 750 mV Direct 750 mV 4.021 3V BR2 3V Direct 3V 1.000 3V BR4 30 V Divide by 101 300 mV 10.000 3V BR3 150/300 V Divide by 101 3V 1.
Theory of Operation A/D Theory of Operations 2 Table 2-5.
268XA Service Manual AC Volts Measurement Circuitry. AC-coupled voltage inputs are scaled by an ac buffer (A3U29), converted to dc by a true RMS ac-to-dc converter (A3U26), filtered by an active ac volt filter, then sent to the Stallion IC, the Buffer Amplifier, and the A/D Conversion Circuitry (see Table 2-6). The HI input is switched to the ac buffer through dc blocking capacitor A3C80. The LO input is sensed through A3L52, A3R146, A3K27, A3R119, and S33 and S37.
Theory of Operation A/D Theory of Operations 2 A3K25 S R A3Q15 A3K25 HI SENSE A3R11 1K 2W FUS R A3C80 A3U29 _ + A3Z6 1.111M A3C72 A3R127 1K A3CR2 LO A3Q12 S A3Z6 12.25K A3Z6 111.1K A3C71 S33 A3L52 A3K27 A3R146 270 R A3R119 1K A3Z6 2.776K A3Z6 115.7 AD LOW VIN RMSOUT A3U26 A3Z2 4.95K To Pin 31 of A3U30 A3R103 100K A3Z2 3.3K S41 A3C57 S44 TO BUFFER AMP A3C58 + _ A3R104 100K A3R102 100K A3C59 f2-10.eps Figure 2-8.
268XA Service Manual Active Filter (ACV Filter) The active filter is used only for V ac measurements to filter out the ac ripple and noise present on the output of the RMS converter. The filter uses an op-amp internal to the Stallion Chip, resistors A3R102, A3R103, and A3R104, capacitors A3C57, A3C58, and A3C59. A3Q6 turns on to discharge the capacitors between measurements. Voltage Reference Circuit The voltage reference circuit creates a well-regulated +3.45/-3.
Theory of Operation A/D Theory of Operations 2 Table 2-7. Analog/Digital Converter Measurement Cycle State Counts Time Autozero 125 200.0 µs Integrate 307 491.4 µs Deintegrate1 64 102.4 µs Deintegrate2 24 38.4 µs Overhead n/a 1.333 µs Total 833.533 µs Integrate The integrate state is when the input voltage is actually connected to the integrator.
268XA Service Manual This can also be anywhere from 1 to 60 counts, but at this point, the output should be within 1 count of reaching zero volts. Next, another hold state is entered into for 1 count, followed by PREF until CMP goes high. This sets up the final DREF to always approach zero from the same direction. A hold state with both references off begins until a total of 64 counts have occurred since deintegrate began.
Theory of Operation A/D Theory of Operations 2 0v dc f2-13.eps Figure 2-11. Integrator Output Waveform for Input Near - Full Scale Deintegrate2 Deintegrate begins with the turning on of DREF. This reference applies 1/16th of the current of NREF so the approach to zero is slower and more accurate. Correspondingly, the internal FPGA counter counts this time at 1/16th the value of NREF time.
268XA Service Manual Communication with the Controller/System Power PCA is done using the CordxRx line to receive and the CordxTx line to send serial data. On the A/D side, these signals are called RECV DATA and XMIT DATA (pins A3U5-53 and A3U5-54 respectively). The RESET* signal is asserted on power-up for reset and during operation when a break signal is received from A1U4. The A/D microprocessor guard crossing is bi-directional.
Theory of Operation A/D Theory of Operations 2 Temperature sensor transistor A4Q1 outputs a voltage inversely proportional to the temperature of the input channel terminals. This voltage is 0.6 V dc at 25 °C, increasing 2 mV with each degree decrease in temperature, or decreasing 2 mV with each degree increase in temperature. For high accuracy, A4Q1 is physically centered within and thermally linked to the 20 input terminals.
268XA Service Manual Commands A command consists of a six-byte packet sent from the outguard to the inguard. The most-significant four bits of the first bytes define the following command types: • Perform Scan. • Perform a Self-Test. • Return A/D Main Firmware Version. • Return A/D Boot Firmware Version. • Set Global Configuration. • Set Channel Configuration. • Do Housekeeping. The sixth byte is a checksum.
Theory of Operation A/D Theory of Operations 2 Response Packets Returned The inguard returns one response packet for the reference junction reading if any of the measured channels is a thermocouple channel, followed by a response packet for each channel measured, returned in ascending channel order, followed by a response packet for each housekeeping reading specified by the scan command.
268XA Service Manual Response Packet Format The response consists of five ASCII characters (plus the checksum byte), in the form Bxxyy, where B indicates boot software, xx are the two digits of the major version number, and yy are the two digits of the minor version number (there is an implicit decimal point between the two). Note that constraining the bytes to be ASCII characters causes the most significant bit of each character to be a 0, making the response packet always distinguishable from a NAK.
Theory of Operation A/D Theory of Operations • If the Next bit is 1, the inguard does the next housekeeping reading indicated by its internal schedule. This is the same schedule used for a housekeeping timeout. • If the Do2 bit is 1, the inguard does the two reference balance readings. • If the PS bit is 1, the inguard presets the function relays for the first defined channel. 2 These bits may be set or cleared independently.
268XA Service Manual The channel scanner relays select the desired channel to be measured and route it to the function relays. The function relays route the signal to the appropriate portion of the Signal Conditioning circuitry, depending on the function being measured (V ac, V dc, ohms, etc.). The Signal Conditioning circuitry converts the signal into a form that can be measured by the A/D (i.e., a dc voltage with a range of -3 to 3 V).
Theory of Operation A/D Theory of Operations 2 Table 2-9. Channel Bits Channels Enabled CH3 CH2 CH1 CH0 1, 11 0 0 0 0 2, 12 0 0 0 1 3, 13 0 0 1 0 4, 14 0 0 1 1 5, 15 0 1 0 0 6, 16 0 1 0 1 7, 17 0 1 1 0 8, 18 0 1 1 1 9, 19 1 0 0 0 10, 20 1 0 0 1 The time required for the channel switches to settle is given in Table 2-10. Note that for both the FAI and the PAI, the switches are guaranteed to have a select time that is longer than their deselect time.
268XA Service Manual Table 2-11. Function Relays Function K26 K25 K27 F0 F1 F2 F3 F4 F5 V dc, TC, OTC S R R 0 1 1 0 1 0 Ohms S R S 0 1 1 0 0 1 V ac, Frequency R S R 1 0 0 1 1 0 Table 2-12. Function Relay Settling Time PAI 6 ms FAI 6 ms Stallion Chip and Signal Conditioning The Stallion Chip (A3U30) is a Fluke-custom IC that contains assorted switches, amplifiers, and the frequency counter.
Theory of Operation A/D Theory of Operations 2 The Stallion switch settings for the various function/range combinations are given in Table 2-13. Table 2-13.
268XA Service Manual Table 2-13.
Theory of Operation A/D Theory of Operations 2 A/D The multi-slope A/D converter in the instrument uses a hardware state machine (A3U18) to control the switching of the voltage references during the A/D conversion. This state machine also contains the counters that measure how long each reference is switched in, and provides the A3U5 A/D microprocessor with its interface to the A/D. A synchronous serial port is used to transfer the counter contents from the state machine to the A3U5 A/D microprocessor.
268XA Service Manual Control Signals Several signals are used by the A3U5 A/D microprocessor to control and receive state information from the A/D state machine (A3U18). The Trigger line, used to indicate to the A/D when to begin a reading, was discussed previously. The A/D state machine has several modes of operation: perform conversion (measure input); do a reference balance reading with both references on; or do a reference balance reading with both references off.
Theory of Operation A/D Theory of Operations 2 Counters The counters in the A/D state machine (A3U18) are accessed through a synchronous serial interface. This interface is connected to the SCP port of the A3U5 A/D microprocessor, which is also connected to the Stallion chip. Chip-select lines are used to indicate the device the A3U5 A/D microprocessor is communicating. The counter values from the A/D are transmitted in five bytes. The hardware state machine transmits bytes most-significant bit first.
268XA Service Manual Z = zero offset. Zero offsets are also covered in “Zero Offset Readings” later in this chapter. DISCHARGE Signal The signal DISCHARGE is driven by the A3U5 A/D microprocessor (pin 59) through one of its parallel port pins and controls the discharge of certain filter capacitors. This line is normally left low. It is driven high during the V ac discharge mode. See “V ac Discharge Mode” later in this chapter for more information.
Theory of Operation A/D Theory of Operations 2 Measurement Types There are several steps that you must perform at the beginning of any channel measurement: • • • • • Set function relays. See “Function Relays” earlier in this chapter. This is a relatively slow operation and should be done only if the relay positions actually need to change. Set tree and channel switches. See “Channel MUX” earlier in this chapter. Program Stallion. See “Stallion Chip and Signal Conditioning” earlier in this chapter.
268XA Service Manual Thermocouple readings also require an isothermal block reference junction reading to be taken. If any thermocouple channels are measured in a scan, a reference junction measurement is taken first, before any channel measurements. Reference Junction The reference junction reading is similar to a V dc reading. However, no channel selection or function relay switching is required; however, the Stallion must be configured.
Theory of Operation A/D Theory of Operations 2 V ac Discharge Mode After a frequency or V ac reading, the hardware is configured to discharge certain signal conditioning capacitors, charged during the measurement. This is done to avoid disturbing the measurement of a subsequent V ac or frequency measurement. The function relays are set to the V ac discharge position, as given in Table 2-11, Function Relays, and the DISCHARGE signal is set high. After 6 ms, the DISCHARGE signal is once again set low.
268XA Service Manual Table 2-18. A/D Reading to Average to Obtain a Reference Balance Measurement Instrument Reading Rate Fast Reading Rate Medium Reading Rate Slow PAI 1 5 (60 Hz) 6 (50 Hz) 45 (60 Hz) 48 (50 Hz) FAI 1 1 5 (60 Hz) 6 (50 Hz) There are two reference balance readings: one with both references on, and one with both references off. These readings are intended to compensate for unequal voltage references in the A/D.
Theory of Operation A/D Theory of Operations 2 Self-Tests There are two series of self-tests performed by the inguard: those done automatically at power-up, and those done in response to a self-test command from the outguard. Power-Up Self-Tests On power-up the inguard performs a ROM checksum test and a destructive RAM test. If either of these tests fail, the inguard treats it as a fatal error and enters the boot monitor. No explicit indication of either of these tests failing is given to the outguard.
268XA Service Manual 2-48
Chapter 3 Maintenance Title Introduction ....................................................................................................... Self-Test Diagnostics and Error Codes ............................................................. Cleaning............................................................................................................. AC Fuse Replacement ....................................................................................... DC Fuse Replacement ...................
268XA Service Manual 3-2
Maintenance Introduction 3 Introduction Maintenance for the 268XA devices is limited to self-test error code explanations, cleaning, and fuse replacemen. Verification and calibration are discussed in Chapters 4 and 5 respectively. Self-Test Diagnostics and Error Codes Self-test diagnostics are performed each time the device is powered up. Any errors encountered during this initial 5 second period are reported on the front panel, as shown below.
268XA Service Manual If the PC card has a configuration in the scan data that is inconsistent with the current module mix, scanning will not begin. When using a PC card, you must either format the PC card or modify the module mix to match the PC card scan configuration before scanning can begin. Table 3-1.
Maintenance Self-Test Diagnostics and Error Codes 3 Table 3-1.
268XA Service Manual Table 3-1. Self-Test Codes (cont) Self-Test Code Description 300 PAI expected in slot 3 301 FAI expected in slot 3 400 PAI expected in slot 4 401 FAI expected in slot 4 500 PAI expected in slot 5 501 FAI expected in slot 5 600 PAI expected in slot 6 601 FAI expected in slot 6 602 DIO expected in slot 6 Cleaning XWWarning Keep the device dry to avoid electrical shock to personnel or damage to the device. To prevent damage, never apply solvents to the device housing.
Maintenance AC Fuse Replacement 3 AC Fuse Replacement The device uses a 1/2 ampere, 250 V, slow blow line fuse in series with the mains power supply. To replace the fuse, refer to Figure 3-1 and the following procedure: XWWarning To avoid electrical shock, do not operate the device without the cover properly installed. 1. Disconnect all rear panel cables to the device power, Universal Input modules, and I/O connectors. 2.
268XA Service Manual DC Fuse Replacement The 2680A/2686A devices use a 4 ampere, 250 V, slow blow fuse in series with the dc supply “+” input. This fuse is mounted on the main controller board inside the chassis. See Figure 3-2 for an illustration of the dc fuse location. Because of potential high voltages, this fuse should only be replaced by a Fluke qualified technician. XWWarning The 268XA chassis contains high voltages that can be dangerous or fatal.
Maintenance DC Fuse Replacement 3 Fuse, 4A, 250V, Slow, 5MM X 20MM, Bulk alg111f.eps Figure 3-2.
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Chapter 4 Performance Verification Title Introduction ....................................................................................................... Configuring the Performance Test Setup ...................................................... Initializing the Performance Test Setup ........................................................ Accuracy Performance Tests ............................................................................. Master Alarm Output Tests...............................
268XA Service Manual Fluke DAQ Totalizer Count and Enable Test........................................... 4-23 Fluke DAQ Totalizer Count and Direction Test....................................... 4-24 Fluke DAQ Totalizer Count and Debounce Test......................................
Performance Verification Introduction 4 Introduction When shipped, the 2680A/2686A is calibrated and in operating condition. The following performance test procedures are provided for acceptance testing upon initial receipt or to verify correct device operation. The performance tests must be performed in sequence. If the device fails a performance test, the device requires service or repair.
268XA Service Manual Table 4-1. Recommended Test Equipment Device Type Minimum Specifications Multifunction Recommended Model DC Voltage: Calibrator Fluke 5700A Range: 90 mV to 300 V dc Accuracy: 0.002% AC Voltage: Frequency Voltage Accuracy 1 kHz 29 mV to 300 V 0.05% 100 kHz 15 mV to 300 V 0.5% Frequency: 10 kHz 1 V rms 0.01% Ohms: Ohms Accuracy 190Ω 0.005% 1.9 kΩ 0.005% 19 kΩ 0.005% 190 kΩ 0.005% 1.9 MΩ 0.
Performance Verification Introduction 4 Unshielded Twisted Pair Cable WITH RX AND TX LINES REVERSED 10/100BaseT RJ-45 Ethernet Ports RJ-45 10/100BaseT Outlets (Typical) Patch Cord Host Computer 1 RJ-45 Interface (Typical) Instrument 10/100BaseT Direct Connection alg04f.eps Figure 4-1. Connection Between Device and Host Initializing the Performance Test Setup Complete the following procedure to initialize the performance test setup.
268XA Service Manual 6. Set network type Set up the device for an isolated network. Note Record the IP address of the device before changing from a general to an isolated network type.The type change will overwrite the existing IP address. 7. Select Module Select the module and slot locations for each module. For each module, insert a Channel 01 and set the channel to 90 mV dc. 8.
Performance Verification Accuracy Performance Tests 4 Master Alarm Output Tests The Master Alarm signal pin is found on the rear chassis 8-pin terminal block connector. This test checks the Master Alarm output signal line for correct logic level operation. See Figure 3-1 for the Master Alarm signal pin location. RS-232 Master Alarm Output Test 1. Connect Test Leads to ALARM/TRIGGER I/O Connector Remove the 8-position ALARM/TRIGGER I/O connector from the device rear panel.
268XA Service Manual 2. Short the Signal to GND Use a wire to short the signal to GND to set the active state. Fluke DAQ Trigger Input Test 1. Configure Trigger Input Using the Fluke DAQ software, configure the scan parameters for External Trigger with an Interval 2 of 1 second. Be sure Interval Trigger and Alarm Trigger are not enabled. 2. Verify Configuration Channel 1 for V dc In Fluke DAQ, verify channel 1 is configured for V dc, 3 V range. 3.
Performance Verification Accuracy Performance Tests 4 9. Stop Scanning Click the Stop Device button on the Button Bar to stop device scanning. Volts DC Accuracy Test (PAI Module) For these tests you must move between the Fluke DAQ Configuration dialog and the Communications dialog. Use the Configuration dialog to set up the analog module channels. Use the Spy option of Communications dialog to view the measurements. All testing is done with channel 1.
268XA Service Manual Volts DC Accuracy Test (FAI Module) The following procedure tests the accuracy of the volts dc function for the 268XA. Measurement accuracy applies to all channels, not just the channel used for the test. 1. Configure Channel 1 for V dc Using the Fluke DAQ software, configure channel 1 for V dc, 90 mV range. 2. Open Spy Open the Spy window under the Configuration dialog. 3.
Performance Verification Accuracy Performance Tests 4 Volts AC Accuracy Test The following procedure tests the accuracy of the volts ac function for both the PAI and FAI modules. Measurement accuracy applies to all channels, not just the channel used for the test. 1. Configure Channel 1 for V ac Using the Fluke DAQ software, configure channel 1 for V ac, 300 mV range. 2. Open Spy Open the Spy window under the Configuration dialog. 3.
268XA Service Manual Analog Channel Integrity Test The following procedure tests the integrity of each analog channel (2 to 20) to verify each analog channel is capable of making measurements. 1. Configure Channel for Ohms Using the Fluke DAQ software, configure channels 2 (then 3, then 4, etc. as this step is repeated) to 20 for Ohms 2W, 300 range [PAI] or 30 k range [FAI]. 2.
Performance Verification Accuracy Performance Tests 4 2-Wire Resistance Accuracy Test (PAI) - Optional Complete the following procedure to test the accuracy of the resistance function for the PAI using 2 terminals. Measurement accuracy applies to all channels, not just the channel used for the test. The 4-wire resistance accuracy test is more rigorous and you may wish to skip this step and continue to 4-Wire Resistance Accuracy Test described later in this chapter. 1.
268XA Service Manual Resistance Range* 300 Ω 300 Ω 3 kΩ 5700A Short Circuit (Zero) 190 Ω Short Circuit (Zero) Minimum Reading Maximum Reading 0Ω 10 Ω 189.91 Ω 200.09 Ω 0Ω 10.5 Ω 3 kΩ 1.9 kΩ 1.8991 kΩ 1.9109 kΩ 30 kΩ 19 kΩ 18.989 kΩ 19.021Ω 300 kΩ 190 kΩ 189.75 kΩ 190.26 kΩ 3 MΩ 1.9 MΩ 1.8942 MΩ 1.9058 MΩ *The resistance accuracy in this table makes allowance for up to 0.1 Ω of lead wire resistance.
Performance Verification Accuracy Performance Tests Resistance Range* Decade Resistor Minimum Reading 4 Maximum Reading 30 kΩ Short Circuit (Zero) 700 Ω 1 kΩ 30 kΩ 29 kΩ 29.681 kΩ 30.019 kΩ 300 kΩ 290 kΩ 289.07 kΩ 292.63 kΩ 3 MΩ 2.9 MΩ 2.8607 MΩ 2.9410 MΩ *The resistance accuracy in this table makes allowance for up to 0.1 Ohm of lead wire resistance plus 0.01% decade resistance tolerance.
268XA Service Manual 4-Wire Resistance Accuracy Test (PAI Module) 1. Connect the Resistance Source to Channels 1 and 11 Remove the Universal Input module from the device and connect a cable from the Decade Resistance Source to the Universal Input module terminals for channel 1 (Sense) and channel 11 (Source) as shown in Figure 4-3. Reinstall the Universal Input module. You may also use the 5700A resistance calibration output instead of the Decade Resistance Source. Tables are provided for both connections.
Performance Verification Accuracy Performance Tests SOURCE 11 12 13 14 15 16 17 18 19 20 HL H L HL HL HL HL HL HL HL HL (4-WIRE) SENSE 4 INPUT MODULE HL H L HL HL HL HL HL HL HL HL (4-WIRE) 1 2 3 4 5 6 7 8 9 10 5700A OUTPUT V ΩA SENSE VΩ WIDEBAND HI HI LO LO HI AUX CURRENT GUARD GROUND NC NC EX SNS : ON EX GRD : OFF 2-WIRE COMP OFF Sense Source UUT 5700A Source Sense alg70f.eps Figure 4-4.
268XA Service Manual 4. Verify Accuracy Configure the Decade Resistance Source for the output values below and verify the Spy window measurement is between the minimum and maximum values. Change the channel 1 range as required (see Step 2). Resistance Range 300 Ω 300 Ω 3 kΩ Decade Resistor Short Circuit (Zero) 290 Ω Short Circuit (Zero) Minimum Reading Maximum Reading 0Ω 0.05 Ω 289.861 Ω 290.139 Ω 0Ω 0.5 Ω 3 kΩ 2.9 kΩ 2.89849 kΩ 2.90137 kΩ 30 kΩ 29 kΩ 28.9834 kΩ 29.
Performance Verification Accuracy Performance Tests 4 4-Wire Resistance Accuracy Test (FAI Module) 1. Connect the Resistance Source to Channels 1 and 11 Remove the Universal Input module from the device and connect a cable from the Decade Resistance Source to the Universal Input module terminals for channel 1 (Sense) and channel 11 (Source) as shown in Figure 4-3. Reinstall the Universal Input module. You may also use the 5700A resistance calibration output instead of the Decade Resistance Source.
268XA Service Manual Resistance Range 300 Ω 5700A Short Circuit (Zero) 300 Ω 3 kΩ Minimum Reading 190 Ω Short Circuit (Zero) Maximum Reading 0Ω 0.1 Ω 189.86 Ω 190.14 Ω 0Ω 1.0 Ω 3 kΩ 1.9 kΩ 1.8986 kΩ 1.9014 kΩ 30 kΩ 19 kΩ 18.986 kΩ 19.014 kΩ 300 kΩ 190 kΩ 188.90 kΩ 191.10 kΩ 3 MΩ 1.9 MΩ 1.8733 MΩ 1.9267 MΩ Digital Input/Output Tests All configuration for the Digital Input/Output Tests is done using the Communications dialog.
Performance Verification Accuracy Performance Tests 4 5. Toggle Each Line Toggle each line and verify that the signal line responds. For example, to toggle DIO0 output, send the command DIO 1048575,1. Physically verify that the signal line is off (high) and then use the DIO? command to read back the setting. Clear the bit using DIO 1048575,0. Physically verify that the signal line is on (low) and then use the DIO? command to read back the setting.
268XA Service Manual 3. Verify Relays Close Verify that relays close by measuring the contact resistance. A contact resistance less than 1 Ω is good. Totalizer Tests The totalizer tests check the correct operation of the totalizer including the direction of counting and the signal level sensitivity. These tests can be run either with RS-232 commands or using Fluke DAQ. For these tests, use the signal generator to generate the counts. The generator will be connected to the totalizer input signal line (Σ).
Performance Verification Accuracy Performance Tests 4 5. Verify Totalizer Count Verify that the totalizer counts from 0 to 4,294,967,295, and then down. 6. Disconnect Signal Generator Disconnect the signal generator. RS-232 Totalizer Count and Debounce Test 1. Initialize Totalizer to 0 Initialize the totalizer to 0 with the TOTINIT command. 2. Set Totalizer to Up Count Set the totalizer to up count with debounce on with the TOTCFG 1,1 command. 3. Set DIO Set DIO 0 to 0 to enable the totalizer. 4.
268XA Service Manual 8. Disconnect Signal Generator Disconnect the signal generator. 9. Select DIO Click on the Communication icon and select the DIO from TreeView. 10. Enable Totalizer Deselect the DIO channel 0 to enable the totalizer. Fluke DAQ Totalizer Count and Direction Test 1. Configure DIO In the Configuration dialog, select the DIO from TreeView. In the DIO Configuration dialog, set the start count to 0, deselect debounce (if selected), and select direction as down. 2.
Chapter 5 Calibration Title Introduction ....................................................................................................... Calibration ......................................................................................................... Methods of Calibration...................................................................................... Preparing for Calibration................................................................................... Ending Calibration...........
268XA Service Manual 5-2
Calibration Introduction 5 Introduction This section of the Service Manual provides a complete set of manual calibration procedures for the 2680A/2686A. The calibration procedures are performed periodically as well as after service or repair. There are no calibration procedures for the 2680A/2686A chassis nor for the DIO module. Only verification tests are run on those items.
268XA Service Manual 2. Wire the Universal Input Module so the high and low inputs to channels 1 and 11 are externally available. In addition, a four-wire short must be applied to channels 2 and 12. (See Figure 5-2.) Plug the module into the device. 3. Power the device and allow at least a 30-minute warm-up period. The device must be stabilized in an environment with an ambient temperature of 22 to 24°C and relative humidity of less than 70%. 4.
Calibration Preparing for Calibration 5 RS43 Null Modem Cable (DB-9 Female to DB-9 Female) RS-232 Port COM1 (DB-9) 268XA Host Computer f4-05.eps Figure 5-1. Device and Host Computer Calibration Setup 11 12 13 14 15 16 17 18 19 20 H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L 1 2 H L CH1 3 4 5 6 7 8 9 10 H L CH11 f4-06.eps Figure 5-2.
268XA Service Manual Ending Calibration When you are using the manual method of calibration and have completed the calibration of the desired functions (dc volts, ac volts, ohms, and frequency), send CAL_MODE OFF to clear CAL from the primary display. RS-232 Device Configuration Parameters When CAL is shown in the 2680A/2686A display, it indicates that you are in the calibration mode. The device configuration parameters are set as listed in Table 5-1. Table 5-1.
Calibration Manual Calibration Procedure Channel 11 Wires SOURCE 11 12 13 14 15 16 17 18 19 20 HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL HL (4-WIRE) SENSE Universal Input Module 2-WIRE COMP OFF (4-WIRE) 1 2 3 4 5 6 7 8 9 5 10 EX SNS : ON EX GRD Channel 1 Wires : OFF 5700A Calibrator OUTPUT VΩA SENSE VΩ WIDEBAND HI HI LO LO HI AUX GUARD GROUND CURRENT f4-08.eps Figure 5-4.
268XA Service Manual f4-06bmp.bmp 5. Select the Terminal Preferences command from the Settings menu. Check the boxes Local Echo and Outbound (see below). Click OK. f4-08bmp.
Calibration Manual Calibration Commands 5 6. Press the key a few times and notice the => returns, indicating a successful connection (see below). If you do not receive these returns, the RS-232 link is not operating. Check the communication parameter settings and cabling. f4-07bmp.bmp Manual Calibration Commands The calibration procedures are performed in the terminal mode using the commands CAL, CAL?, CAL_REF, CAL_REF?, CAL_STEP, and CAL_CLR.
268XA Service Manual Table 5-3. Manual Calibration Command Responses Response Description => indicates the command was executed correctly. !> indicates that a device-dependent error was generated and the calibration step could not be executed. Verify that the input to channel 1 is the correct value and polarity, is connected correctly, and the 5700A is in the Operate mode. ?> indicates the command was entered with incorrect syntax, for example, misspelling the command.
Calibration Manual Calibration Commands 5 Table 5-4. Manual V DC Calibration Command CAL 1 Response => Action Puts 268XA in V dc calibration. CAL_REF? +90.0000E-3 Use the 5700A to source 90 mV dc. CAL_STEP? +90.0000E-3 268XA computes the calibration constant and returns the calibrated reading. Allow several seconds. CAL_REF? +300.000E-3 Use the 5700A to source 300 mV dc. CAL_STEP? +300.000E-3 268XA computes the calibration constant and returns the calibrated reading. Allow several seconds.
268XA Service Manual V AC Calibration Procedure The V ac calibration procedure calculates gain and offset calibration constants for all of the V ac ranges. Complete the following procedure to manually calibrate the V ac function. 1. If you have not already done so, complete the procedure “Preparing for Calibration” earlier in this chapter. 2. Connect the device and 5700A Calibrator as shown in Figure 5-3. 3. Complete the sequence of manual steps shown in Table 5-5.
Calibration Manual Calibration Commands 5 Table 5-5. Manual V AC Calibration Command Response Action CAL 2 => Puts 268XA in V ac calibration. CAL_REF? 30.0000E-3 Use the 5700A to source 30 mV ac @ 1 kHz CAL_STEP? 30.0000E-3 268XA computes the calibration constant and returns the calibrated reading. Allow several seconds. CAL_REF? 300.000E-3 Use the 5700A to source 300 mV ac @ 1 kHz CAL_STEP? 300.000E-3 268XA computes the calibration constant and returns the calibrated reading.
268XA Service Manual channel 1 provides the full scale reading and measuring the four-wire short on channels 2 and 12 determines the zero offset error. The four-wire ohms gain and offset calibration constants are determined from these two measurements. The 5700A provides a limited set of reference resistors where the best resistor for each range is at 63.3% of full scale.
Calibration Manual Calibration Commands 5 Table 5-6. Manual Resistance Calibration Command Response Action CAL 3 => Puts 268XA in resistance calibration. CAL_REF? +190.000E+0 Use the 5700A to source 190 Ω. CAL_STEP? +190.000E+0 268XA computes the calibration constant and returns the calibrated reading. Allow several seconds. CAL_REF? +1.90000E+3 Use the 5700A to source 1.9 kΩ. CAL_STEP? +1.90000E+3 268XA computes the calibration constant and returns the calibrated reading.
268XA Service Manual • An execution error !> is returned by the CAL_STEP? command if the frequency measurement is off by more than 5% from the target. When an error is detected, the cal constant is not updated, and the procedure remains at the same step. • When CAL_STEP? reports an execution error !> due to an out-of-range measurement, it returns the raw measured reading to give you an indication of what was measured. When CAL_STEP? completes successfully, it returns the reference value.
Chapter 6 Diagnostic Testing and Troubleshooting Title Introduction ....................................................................................................... Servicing Surface-Mount Assemblies ............................................................... Error Detection .................................................................................................. FLASH ROM Parameter Defaults ................................................................ Background Testing ...........
268XA Service Manual Totalizer Enable........................................................................................ Digital Output PCA Troubleshooting ........................................................... A3 A/D Converter Module Troubleshooting ................................................ A3 Kernel.................................................................................................. Break/Reset Circuit..........................................................................
Diagnostic Testing and Troubleshooting Introduction 6 Introduction The 268XA device provides error code information and semi-modular design to aid in troubleshooting. This section explains the error codes and describes procedures needed to isolate a problem to a specific functional area. Finally, troubleshooting hints for each functional area are presented. First, if the device fails, check the line voltage fuse and replace as needed.
268XA Service Manual especially clean to ensure a strong connection. An oxidized PCA pad causes the solder to wick up the component lead, leaving little solder on the pad itself. Error Detection At power-up, the device software performs self-tests. If any errors in device operation are detected, they are reported on the device front panel with Error in the primary display and a decimal error code number in the secondary display. If there is more than one error, they are displayed sequentially.
Diagnostic Testing and Troubleshooting Error Detection 6 Table 6-1.
268XA Service Manual Table 6-1. Self-Test Error Codes (cont) Front Panel Err Self-test Code Description Second 32-bit self-test code 6-6 0x00000000 No self-test error.
Diagnostic Testing and Troubleshooting Error Detection 6 FLASH ROM Parameter Defaults The FLASH ROM (System Power/Controller Board 2680A-4004) parameters are reset to defaults following the first power-on and following power-cycles after any FLASH ROM parameters are discovered to be corrupt. These defaults are listed in Table 6-2. Table 6-2.
268XA Service Manual Retrieving Error Codes using RS-232 You can retrieve error codes from the device using the device rear-panel RS-232 port and an ASCII terminal, or PC running ASCII terminal emulation. Complete the following procedure to retrieve error codes from the device using an RS232 connection. 1. Connect the device to a PC COM port and setup the RS-232 parameters and connection as described in the procedure “Manual Calibration Procedure” in Chapter 5. 2.
Diagnostic Testing and Troubleshooting Selecting the Diagnostic Tools 6 1. Select the dio diagnostic tool using the procedure “Selecting the Diagnostic Tool Menu.” 2. Use the left/right arrows to select the desired dio line dio19 to dio0. The format is nnnn-nnnn-nnnn-nnnn-nnnn, representing dio lines dio19 to dio0, respectively. The secondary display shows the selected line, for example, dio:19. 3. Use the up/down arrow keys to select the desired dio line status, 0 or 1. 4.
268XA Service Manual Table 6-4. Device Firmware Descriptions Primary Display* Secondary Display 2680A -or- 2686A inStr (Device Model Number) 01.00 Lc (logger GUI compatibility e.g.. embedded is compatible with GUI version 1 or higher) 02.00 diSP (Display CPU Version) 1.2-1 boot (Main Boot Version) 01.00 MAin (Main Software Version) * The firmware versions shown in this table are typical. Actual firmware versions may vary. ** Field Programmable Gate Array 3.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 Diagnostic Display Test For a constant front panel display with all segments lit, turn off the device, then turn the power on again while holding down the front panel key. After the device beeps, release the key. The front panel display remains on until any front panel key is pressed. This allows you to inspect the display segments.
268XA Service Manual An input line to the device consists of one or more semicolon-separated commands followed by an input terminator. The device will accept CR/LF or LF as the input terminator. The device reads input into a 350-byte input queue until it finds the input terminator. The device does not echo input. While processing the queued input, the device parses and processes each command in sequence. Therefore, earlier commands can execute even if a later command contains a syntax error.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 Table 6-6.
268XA Service Manual Table 6-7.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 Table 6-7.
268XA Service Manual = 6 character string: “P” for PAI; “F” for FAI; “D” for DIO; “-“ for no module installed: ie, “PP-F-D” Restrictions: None Notes: None Command: *OPC? Description: Operation complete query. *OPC? causes 268XA to output an ASCII ‘1'. Parameters: None Response: = 1 Restrictions: None Notes: *OPC? is used in conjunction with a non-query command to get a response from 268XA when the non-query command is finished executing.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 Response: , = two integers which binary-encodes the self-test results as shown in Tables 6-1: self-test codes. Restrictions: Not allowed in calibration mode.
268XA Service Manual = integer 1 - 6 = integer 0 - 60 (even integers only) Response: = floating point calibration constant Restrictions: None Notes: The Calibration Constants section describes the calibration constants in detail.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 This command returns an execution error if no cal procedure is active. This command returns a device dependent error if an internal error such as measurement timeout is detected. If the CAL_STEP? command completes successfully, the “calibrated value” returned is the reference value. If the command fails because the measured reading is outside of the specified limits, the raw measurement is returned.
268XA Service Manual may be specified for FREQ, but it is not used. a value which is ‘na' in Table 6-8: Range Settings generates an execution error. Notes: On the 268XA PAI, channels 1 and 11 can measure 300V while the other channels can measure only 150V. When configuring for 4-wire ohms, only channels 1-10 can be used; channels 11-20 must be OFF or a device dependent error is generated. Thermocouple: FUNC 101, TC, K, 1 Thermistor: FUNC 102, THERM, AUTO, 2, 0.0014733, 0.0002372, 1.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 When is OHMS, is always returned.
268XA Service Manual Command: DIO? Description: Get the value of the DIO Digital lines 0 through 19 Parameters: None Response: 0 to 1048575 (2^20 – 1) Restrictions: None.
Diagnostic Testing and Troubleshooting Using the RS-232 Interface 6 Restrictions: None. Notes: None. Command: TOT? Description: Get the value of the DIO Totalizer Parameters: None Response: 0 to 2^32 (4,294,967,296) Restrictions: None. Notes: None. Command: TOTCFG , Description: Set the value of the DIO Totalizer configuration Parameters: = 0 for down, 1 for up; = 0 for off, 1 for on Response: None Restrictions: None. Notes: None.
268XA Service Manual Command: RATE? Description: Get the scan speed Parameters: : integer from 1 to 6 Response: FAST, MEDIUM, SLOW Restrictions: None. Notes: None. Command: SERIAL? Description: Get the serial number for a module Parameters: integer from 1 to 6 Response: programmed serial # Restrictions: None.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Command: MAOUT <1 or 0> Description: Force the Master Alarm ON (Logic Low) or OFF (Logic High) Parameters: 1 (ON - Logic Low) or 0 (OFF - Logic High) Response: None. Restrictions: None Notes: None. Troubleshooting the Device The following paragraphs describe an organized method of device troubleshooting. The overall approach is to start with power-up self-test error codes and then proceed too increasingly detailed procedures.
268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems Error Code 1 Error Code Description Bad boot software image in FLASH ROM. Suspect Assembly Sys/Ctrl PCA Error Code Discussion Background The System Power/Controller Board FLASH memory device, U20, is divided into sections. One of these sections is the memory for the boot software, which is used for device initialization. After the device is initialized, the main code takes over and runs the device.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 4 Error Code Description Display test failure. Suspect Assembly Error Code Discussion A2 Display PCA [Note 1] Background The SYS/CTRL microprocessor requests the A2 Display PCA to run a self-test and report the results. Failure For this error to occur, the A2 Display PCA is able to communicate with Sys/Ctrl microprocessor but the Display self-test is “fail.
268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 7 Error Code Description Module 1 Procedures Incomplete. Suspect Assembly Module PCA Error Code Discussion Background Each module of the 2680A/2686A contains its own calibration constants on the A/D Power daughter card. The A/D U7 FLASH memory device contains the calibration constants. The calibration constants are used by the A/D converter.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code Error Code Description Suspect Assembly Error Code Discussion 10 Module 1 reference balance test failed. A3 A/D Converter PCA Background The A/D converters uses two very precise voltages for operation: +3.45 V dc and -3.45 V dc. These voltages are applied to resistor network A3Z1-1 and A3Z1-3, with a balanced output at A3Z1-2.
268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 12 Error Code Description Suspect Assembly Error Code Discussion Module 1 open thermocouple detect failed. A3 A/D Converter PCA Background The open thermocouple detect circuit checks on the amount of a 19.2 kHz voltage developed across a “thermocouple.” Similar to the overload detection, the self-test does not set any channel relays and the detection circuit should detect the “open” thermocouple.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 15 Error Code Description RAM constants corrupt. Suspect Assembly Sys/Ctrl PCA Error Code Discussion Background The SYS/CTRL stores constants in flash memory, U20, which are transferred to RAM for use in operation. Failure For this error to occur, the constants may be improperly stored in the SYS/CTRL RAM or flash.
268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 23 Error Code Description Suspect Assembly Module 2 open thermocouple detect failed. A3 A/D Converter PCA Error Code Discussion Background Same as for module 1. Failure Same as for module 1. Correction Same as for module 1.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code 41 Error Code Description Module 4 A/D failure Suspect Assembly Module PCA Error Code Discussion Background Same as for module 1. Failure Same as for module 1. Correction Same as for module 1.
268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Code Error Code Description 51 Module 5 Overload detection failed Suspect Assembly Module PCA Error Code Discussion Background Same as for module 1. Failure Same as for module 1. Correction Same as for module 1. 52 Module 5 Open thermocouple detection failed Module PCA Background Same as for module 1. Failure Same as for module 1. Correction Same as for module 1.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-10. Hints for Troubleshooting "Dead" Devices Possible Fault Discussion Blown Fuse If the device is completely dead, you may have blown the line fuse. There is also a fuse inline with the DC voltage input for battery input protection. Either power input can operate without the other working. See Chapter 3 for fuse replacement instructions. Power Supply Self-test starts with the outguard Sys/Ctrl PCA.
268XA Service Manual Sys/Ctrl PCA Troubleshooting The following paragraphs provide troubleshooting hints for the Sys/Ctrl PCA. Use this material in conjunction with Chapter 2, “Theory of Operation.” XWWarning To avoid electric shock, disconnect all power and channel inputs from the device before performing any troubleshooting operations. Troubleshooting the Sys/Ctrl PCA Digital Kernel The processor on the SYS/CTRL card is a MPC855T packaged in a ball grid array.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Troubleshooting the Ethernet Interface If Ethernet interface does not operate properly, there are several things to check. When the interface is hooked to a network, the Link LED should light (green) and the RECV LED should blink red. If that does not happen, check U17 pins for a nominal +5 V dc. U17 is powered by power supply component U303. Check that U16 provides the correct 25 MHz frequency to U17.
268XA Service Manual Table 6-11. A2 Display PCA Initialization Routines A2TP4 DTEST* A2TP5 LTE* Power-Up Display Initialization 1 1 All segments OFF 1 0 All segments ON (default) 0 1 Display Test Pattern #1 0 0 Display Test Pattern #2 Figures 6-1 and 6-2 show Display Test Patterns #1 and #2, respectively. REM SCAN REVIEW SET FUNC mV x1 k Ω 1 EXT TR f5-01.eps Figure 6-1. Display Test Pattern #1 LAST MAX MIN F AUTO MON Mx+B ALARM C F RO AC DC Hz M LIMIT HI OFF PRN CH 2 LO CAL f5-02.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 4. Check the state of the RESET signal (A2U1-1). This signal should be low once the reset time is completed (after power-up). Also verify that the RESET* signal (A2U6-3) is high after the reset time is completed. 5. Verify that the DISRX signal (A2U1-39) goes low after RESET (A2U1-1) goes low. If this sequence does not occur, communication to the Microprocessor is held off with the DISRX signal high.
268XA Service Manual PCMCIA PCA Troubleshooting The PCMCIA interface board mainly consists of a card holder and a set of bi-directional level shifting buffers. The buffers on this board are driven off the same supply as the card, which can be either 3.3 V or 5 V. The buffers on A4 board are always powered from Vcc (3.3 V). This board also has a 5 V to 12 V boost topology switching regulator that is only turned on if the installed card says that it needs 12 V for programming.
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Digital Input Buffers The Digital Input Threshold circuit sets the input threshold level for the Digital Input Buffers and the Totalizer Input. A fixed value voltage divider (R5, R6) and a unity gain buffer amplifier (U1) are the main components in the circuit. The voltage from the divider (approximately +1.4 V dc) is then buffered by U1, which sets the input threshold. Capacitor C8 filters the divider voltage at the input of U1.
268XA Service Manual Totalizer Input The Totalizer Debounce circuit in the PLD (U3) allows the micro controller to select totaling either the input signal or the debounced input signal. The buffered Totalizer Input signal (TOT_IN) goes into the PLD at U3 Pin 13. U3 Pin 9 is the debounce enable control signal. It is active high ( HI = Totalizer Debounced, Lo = Totalizer NOT Debounced). The Totalizer output from the PLD is on U3 Pin 23 and this signal goes to the micro controller (CIN U4 Pin 2).
Diagnostic Testing and Troubleshooting Troubleshooting the Device 6 Table 6-12. A3 A/D Converter PCA Jumper Positions Jumper If Missing If in Place W5 VBOOT enable at A3Q1 (this jumper is in place when loading new A/D firmware.
268XA Service Manual Troubleshooting Relay Problems Both the PAI and FAI use mechanical reed relays for signal switching, although the FAI uses solid-state relays for channel selection. The mechanical relays have a life of 100,000,000 operations. If you use your device in long-duration, high-speed measurement runs at high voltages and high common mode voltages, then the relays may start to act up after a few years. This includes failure to open, failure to close, excessive contact resistance, and so forth.
Diagnostic Testing and Troubleshooting Troubleshooting Calibration Failures • • 6 Check the output of the calibration source. Does it equal the value called for by this calibration step? Check the calibration source.
268XA Service Manual Table 6-13. A/D Module Calibration Constants CAL Constant Number Function Range Function Maximum Allowable Value 0 V dc 90 mV Gain +0.95000E+0 +1.05000E+0 2 V dc 90 mV Offset -0.00090E+0 +0.00090E+0 4 V dc 300 mV Gain +0.95000E+0 +1.05000E+0 6 V dc 300 mV Offset -0.00300E+0 +0.00300E+0 8 V dc 3V Gain +0.95000E+0 +1.05000E+0 10 V dc 3V Offset -0.03000E+0 +0.03000E+0 12 V dc 30 V Gain +0.95000E+0 +1.05000E+0 14 V dc 30 V Offset -0.
Diagnostic Testing and Troubleshooting FlukeDAQ Software 6 The frequency counter calibration constant is simply the Gain constant calculation where the lowTarget and lowMeas are both assumed to be zero. FrequencyConstant = targetFreq / measFreq To retrieve the calibration constants, set up the device in the manual calibration configuration described in “Manual Calibration Procedure“ in Chapter 5.
268XA Service Manual 6-48
Chapter 7 Replaceable Parts Title Introduction ....................................................................................................... How to Obtain Parts .......................................................................................... Service Centers.................................................................................................. Parts Lists ..........................................................................................................
268XA Service Manual 7-2
Replaceable Parts Introduction 7 Introduction This chapter contains lists of replaceable parts for the 268XA Data Acquisition/Data Logging System devices. Parts are listed by assembly. Each assembly is accompanied by an illustration showing the location of each part and a number which you can use to locate a part in the parts list. The parts lists provide the following information: • Reference Numbers refer to the circle numbers on the illustrations.
268XA Service Manual Parts Lists The following tables list the replaceable parts for the 268XA devices. Caution PCAs may be subject to damage by static discharge.
Replaceable Parts Parts Lists 7 Table 7-1. 2680A Final Assembly Parts List Number Part Number Reference Designator 2W 109322 3 424416 4 1598923 2680A-4004 PCA, SYSTEM POWER AND CONTROLLER 5 295105 SCREW,SCREW,CAP,SCKT,SS,8-32,.375 6 109998 7 1619985 2680A-8002, 2680A FRONT PANEL DECAL 8 1598783 2680A-4001,PCA, BACK PLANE 9 284174 A99MP1 LC1 LINE CORD,NORTH AM,10A,5-15/IEC,18/3,SVT,7.
268XA Service Manual Table 7-1. 2680A Final Assembly Parts List (cont) 7-6 Number Part Number Reference Designator 29 1560703 A63MP2 FLUKE 45-4021-01, ,ASSEMBLY DISPLAY 30 1593113 A63MP3-4 A65MP4-5 2680A-2021,HANDLE PLASTIC 8.75 IN.
Replaceable Parts Parts Lists 7 Table 7-2. 2686A Final Assembly Parts List Number 2 W Part Number Reference Designator 109322 Description FUSE,FUSE,.25X1.25,0.5A,250V,SLOW 3 424416 A65MP9 4 1598923 2680A-4004 PCA, SYSTEM POWER AND CONTROLLER 5 295105 SCREW,SCREW,CAP,SCKT,SS,8-32,.375 6 109998 7 1667870 2686A-8001,2686A FRONT PANEL DECAL 8 1598783 2680A-4001,PCA, BACK PLANE 9 284174 A99MP1 LC1 LINE CORD,NORTH AM,10A,5-15/IEC,18/3,SVT,7.
268XA Service Manual Table 7-2. 2686A Final Assembly Parts List (cont) Number 7-8 Part Number Reference Designator Description 28 1610650 A64T1 TRANSFORMER,POWER,230V,50/60HZ,8.43:1,130W,CHASSIS MOUNT,BULK 29 1560703 A63MP2 FLUKE 45-4021-01, ,ASSEMBLY DISPLAY 30 1593113 A63MP3-4 A65MP4-5 2680A-2021,HANDLE PLASTIC 8.75 IN.
Replaceable Parts Parts Lists 7 Table 7-2. 2686A Final Assembly Parts List (cont) Number Part Number Reference Designator Description 62 769422 LC3 LINE CORD,CONT EURO,10A,CEE-7/IEC,1MM/3,2.5M 63 1777348 CONNECTOR ACCESSORY,D-SUB JACK SCREW,4-40,.250 L,W/FLAT WASHER 65 172080 CABLE ACCESSORY,CABLE ACCESS,TIE,4.00L,.10W,.
268XA 268X FINAL ASSEMBLY Service Manual alg105f.eps Figure 7-1.
Replaceable Parts Parts Lists 7 Table 7-3. Blank Module Parts List Number Part Number Reference Designator Description 2 1593050 2680A-2015, MODULE REAR PANEL 3 1669653 2680A-2013,BLANK MODULE BRACKET 4 1669889 2680A-8011,BLANK MODULE DECAL 2680A-BLANK alg101f.eps Figure 7-2.
268XA Service Manual Table 7-4. DIO Module Parts List Number 7-12 Part Number Reference Designator Description 2 1598906 2680A-4006,PCA, DIGITAL IO AND RELAY 3 1593050 2680A-2015, MODULE REAR PANEL 4 152173 SCREW,6-32,.500,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 5 1593045 2680A-2011, FAI/PAI MODULE COVER 6 376822 SCREW,SCREW,PH,P,LOCK,SS,6-32,.750 7 1610886 2680A-2008, DIO MODULE BASE 8 152140 SCREW,6-32,.
Replaceable Parts Parts Lists 7 2680A-DIO alg100f.eps Figure 7-3.
268XA Service Manual Table 7-5. FAI Module Parts List Number 7-14 Part Number Reference Designator Description 2 1593050 2680A-2015, MODULE REAR PANEL 4 152173 SCREW,6-32,.500,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 5 1593045 2680A-2011, FAI/PAI MODULE COVER 6 376822 SCREW,SCREW,PH,P,LOCK,SS,6-32,.750 7 152140 SCREW,6-32,.250,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 8 1593038 2680A-2010, FAI/PAI MODULE BASE 9 939723 A45MP203 10 757294 A45MP95-96 JUMPER,JUMPER,REC,2 POS,.100CTR,.
Replaceable Parts Parts Lists 7 2680A-FAI alg102f.eps Figure 7-4.
268XA Service Manual Table 7-6. PAI Module Parts List Number 7-16 Part Number Reference Designator A40MP203 Description 2 939728 3 1593050 2680A-2015, MODULE REAR PANEL 5 152173 SCREW,6-32,.500,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 6 1593045 2680A-2011, FAI/PAI MODULE COVER 7 376822 SCREW,SCREW,PH,P,LOCK,SS,6-32,.750 8 152140 SCREW,6-32,.250,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 9 1593038 2680A-2010, FAI/PAI MODULE BASE 10 757294 A40MP95-96 JUMPER,JUMPER,REC,2 POS,.100CTR,.
Replaceable Parts Parts Lists 7 2680A-PAI alg103f.eps Figure 7-5.
268XA Service Manual Table 7-7. Isothermal Input Parts List Number Part Number Reference Designator Description 39 949537 A04MP204 2620A-4004A,INPUT PWB ASSY,A4 274 698027 A14MP90 Y9XXX-8002,BAG, LARGE ACCESSORY 281 874107 A14MP2 2620A-2007,ISOTHERMAL CASE,BOTTOM 282 874110 A14MP3 2620A-2008,ISOTHERMAL CASE,TOP 389 1669892 398 876479 998 1259450 2680A-8012,ISOTHERMAL CASE DECAL A14H65 SCREW,SCREW,KNURL,SL,CAPT,STL,6-32,.500 FACTORY BASE WARRANTY, 1 YEAR 2620A-180 alg104f.
Chapter 8 Schematics Figure 8-1. 8-2. 8-3. 8-4. 8-5. 8-6. 8-7. 8-8. 8-9. 8-10. 8-11. 8-12. Title Backplane PCA...................................................................................................... Controller/System Power PCA .............................................................................. Digital I/O PCA ..................................................................................................... Backplane Extender PCA ................................................
268XA Service Manual 8-2
Schematic Diagrams 8 2680A-4001 Figure 8-1.
268XA Service Manual 2680A-1001 Figure 8-1.
Schematic Diagrams 8 2680A-4004 Figure 8-2.
268XA Service Manual 8 7 6 REF DES U2,U28,U29 U4,U5,U10 D U6 C U27 PARTNAME 244_VHC 16245_LCX 5 GND 10 4,10,15 21,28,34 39,45 MPC855_ALT F6,F7,F8 F9,F10 F11,F12 F13,F14 G6,G7,G8 G9,G10 G11,G12 G13,G14 H6,H7,H8 H9,H10 H11,H12 H13,H14 J6,J7,J8 J9,J10 J11,J12 J13,J14 K6,K7,K8 K9,K10 K11,K12 K13,K14 L6,L7,L8 L9,L10 L11,L12 L13,L14 M6,M7,M8 M9,M10 M11,M12 M13,M14 N6,N7,N8 N9,N10 N11,N12 N13,N14 P6,P7,P8 P9,P10 P11,P12 P13,P14 240_AC 10 VCC 4 3 2 2 VCC_U6 20 7,18,31 42 D A8,H19,M1 W8,E5,E6 E7,
Schematic Diagrams 8 7 6 5 4 3 2 8 1 BACKPLANE CONNECTOR +5V 10/100 BASE-T ETHERNET TRANSCEIVER P3 B VCC C29 0.1U CARD3_RX OUT CARD3_TX + C28 C39 + C42 C40 IN 10U 0.1U 10U 0.1U + C146 C147 10U 1 34 TX_EN/10TXEN 0.1U 1 2 3 IN IN CLOCK V+ 1 CARD4_RX OUT U16 OUT -INH 25.0MHZ GND 3 2 CARD4_TX IN GUARDCK4 GUARDCK4* IN IN IN R181 5 49.9 7 9 ANEGA CARD5_TX IN 61 RPTR GUARDCK5 GUARDCK5* IN IN 72 74LCX125 14 L37 2 DISPLAY_RST* 3 OE R87 R88 10.
268XA Service Manual 8 7 6 5 4 3 2 1 DQM CKE CLK 37 38 BA0 BA1 20 21 POE* IN SDRAM_CK 8 7 48 39 10.0K 1 BSA3* R141 10.0K R195 10.
Schematic Diagrams 8 7 6 WP4 5 4 3 2 D 5 6 7 10U VCC C141 0.01U + C130 10U C116 C121 C122 C123 C124 C125 C126 C127 C129 C131 C132 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U D 3 + C152 LT1763 1 IN OUT 2.5V 2 SHDN SENSE 4 GND BYP GND GND 1 FPGA AND SUPPORT +2.5V U24 8 VCC_U25 8 C94 C97 C100 C103 C106 C109 C112 R144 C61 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 1K 5% 0.
268XA Service Manual 8 7 6 5 4 3 2 1 CR315 BAV74 POWER SUPPLIES AND DECOUPLING C307 0.1U CR301 D +8V MIN +45V MAX DC INPUT FROM REAR PANEL (9-42V) MBRD360 P6 F301 1 3 2 1 4 CR302 2 4 3 VCC 3 16 S O L306 CAP 3.
Schematic Diagrams 8 2680A-4006 Figure 8-3.
268XA Service Manual 2680A-1006 (1 of 3) Figure 8-3.
Schematic Diagrams 8 2680A-1006 (2 of 3) Figure 8-3.
268XA Service Manual 2680A-1006 (3 of 3) Figure 8-3.
Schematic Diagrams 8 2680A-4009 Figure 8-4.
268XA Service Manual 2680A-1009 Figure 8-4.
Schematic Diagrams 8 2680A-4010 Figure 8-5.
268XA Service Manual 2680A-3010 Figure 8-5.
Schematic Diagrams 8 2680A-4031 Figure 8-6.
268XA Service Manual 2680-1031 Figure 8-6.
Schematic Diagrams 8 2680A-4041 Figure 8-7.
268XA Service Manual 2686-1041 Figure 8-7.
Schematic Diagrams 8 2680A-4062 Figure 8-8.
268XA Service Manual 2680A-1062 Figure 8-8.
Schematic Diagrams 8 2640A-4003 Figure 8-9.
268XA Service Manual (1 of 6) Figure 8-9.
Schematic Diagrams 8 (2 of 6) Figure 8-9.
268XA Service Manual 2640A-1003 (3 of 6) Figure 8-9.
Schematic Diagrams 8 2640A-1003 (4 of 6) Figure 8-9.
268XA Service Manual 2640A-1003 (5 of 6) Figure 8-9.
Schematic Diagrams 8 2640A-1003 (6 of 6) Figure 8-9.
268XA Service Manual 2645A-4003 Figure 8-10.
Schematic Diagrams 8 2645A-1003 (1 of 6) Figure 8-10.
268XA Service Manual 2645A-1003 (2 of 6) Figure 8-10.
Schematic Diagrams 8 2645A-1003 (3 of 6) Figure 8-10.
268XA Service Manual 2645A-1003 (4 of 6) Figure 8-10.
Schematic Diagrams 8 2645A-1003 (5 of 6) Figure 8-10.
268XA Service Manual 2645A-1003 (6 of 6) 700p29_topress.zip Figure 8-10.
Schematic Diagrams 8 2620A-4004A Figure 8-11.
268XA Service Manual 2620A-1004 Figure 8-11.
Schematic Diagrams 8 (1 of 1) Figure 8-12.
268XA Service Manual (1 of 1) Figure 8-12.
