SCXI ™ SCXI-1127/1128 User Manual SCXI-1127/1128 User Manual December 2000 Edition Part Number 322149B-01
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Important Information Warranty The SCXI-1127 and SCXI-1128 are warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This warranty includes parts and labor.
Compliance FCC/Canada Radio Frequency Interference Compliance* Determining FCC Class The Federal Communications Commission (FCC) has rules to protect wireless communications from interference. The FCC places digital electronics into two classes. These classes are known as Class A (for use in industrialcommercial locations only) or Class B (for use in residential or commercial locations). Depending on where it is operated, this product could be subject to restrictions in the FCC rules.
• • Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. Consult the dealer or an experienced radio/TV technician for help. Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations. Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.
Conventions The following conventions are used in this manual: <> Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name—for example, DBIO<3..0>. » The » symbol leads you through nested menu items and dialog box options to a final action. The sequence File»Page Setup»Options directs you to pull down the File menu, select the Page Setup item, and select Options from the last dialog box.
Contents Chapter 1 Installing and Configuring the SCXI-1127/1128 Installing the Software ...................................................................................................1-2 Installing the Hardware..................................................................................................1-3 Installing the SCXI-1127/1128 Module into the SCXI Chassis......................1-4 Connecting the SCXI-1127/1128 to the DMM in a Single-Chassis System...1-5 Single 4-Slot Chassis Configuration .
Contents Hardware-Timed Scanning Using a DMM ........................ 2-14 Hardware-Timed Scanning Using External Instruments ... 2-14 Synchronous Scanning ....................................................... 2-14 Handshaking Scanning....................................................... 2-15 Software Scanning ............................................................................ 2-17 Making Temperature Measurements ..............................................................
Contents Glossary Index Figures Figure 1-1. Figure 1-2. Figure 1-3. Figure 1-4. Figure 1-5. Figure 1-6. Figure 1-7. Figure 1-8. Figure 1-9. Figure 2-1. Figure 2-2. Figure 2-3. Figure 2-4. Figure 2-5. Figure 2-6. Figure 2-7. Figure 2-8. Figure 2-9. Figure 2-10. Figure 2-11. Figure 2-12. Figure 2-13. Figure 2-14. Figure 2-15. Figure 2-16. Figure 2-17. Figure 2-18. Figure 2-19. Figure 2-20. Figure 2-21. Figure 2-22. Figure 2-23. Installing the SCXI-1127/1128 into an SCXI Chassis ..........................
Contents Figure 2-24. Figure 2-25. Figure 2-26. 8 × 16 Matrix Parts Locator Diagram ................................................... 2-27 8 × 16 Matrix Schematic....................................................................... 2-28 SCXI-1127/1128 Relay Configuration ................................................. 2-30 Figure C-1. Figure C-2. Removing the SCXI Module Cover...................................................... C-1 Bent and Trimmed Resistor ......................................
1 Installing and Configuring the SCXI-1127/1128 The SCXI-1127 and SCXI-1228 modules are high-voltage multiplexer/matrix modules. The SCXI-1127 is a high-density armature relay module. The SCXI-1128 is a high-density solid-state relay module. Both modules provide a 1 × 32, 2-wire multiplexer and several switch matrix configurations on an SCXI platform.
Chapter 1 Installing and Configuring the SCXI-1127/1128 In a matrix configuration, you can expand the columns of the matrix using the HVAB-backplane adapter. For example, you can connect two SCXI-1127/1128 modules via the HVAB-backplane adapter to create a 4 × 16 matrix. You can also expand the rows and columns of a matrix through the front connector of the SCXI-1127/1128 using the SCXI-1332 and matrix expansion cables. Refer to Chapter 2, Matrix Expansion, for further information on matrix expansion.
Chapter 1 Installing and Configuring the SCXI-1127/1128 The NI-SWITCH and NI-DMM version 1.5 installation window offers three choices: 3. • Install NI-DMM—Choose this selection if you want to install only the software for the DMM. • Install NI-SWITCH—Choose this selection if you want to install only the software for the switches. • Install NI-SWITCH and NI-DMM—Choose this selection if you want to install the software for both the DMM and the switches.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Installing the SCXI-1127/1128 Module into the SCXI Chassis You need the following items to complete the installation: • SCXI-1127/1128 • SCXI chassis • 1/8 in. flathead screwdriver 1 2 10 3 4 9 5 8 7 6 1 2 3 4 AB0+ AB0– NI 4060 for PCI AB2+ 5 6 7 AB2– HV8-BAN4 SH9MD-9MD 8 2-Slot HVAB-Backplane Adapter 9 SCXI Chassis 10 SCXI-1127/1128 Module Figure 1-1.
Chapter 1 Installing and Configuring the SCXI-1127/1128 When installing the SCXI-1127/1128 module in an SCXI chassis, the rightmost slot (when the chassis is viewed from the front) must be filled first, then fill the slot to the left with the next SCXI-1127/1128. Other SCXI modules can be loaded from left to right. Note 4. Insert any other SCXI modules into the remaining slots in the same manner as described in step 3. 5.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Single 4-Slot Chassis Configuration Refer to Figures 1-2 and 1-3 to make connections in the single 4-slot chassis configuration. 1 6 2 3 4 5 7 8 1 2 3 SCXI-1127/1128 Module 4-Slot SCXI Chassis 2-Slot HVAB-Backplane Adapter 4 5 1-Slot HVAB-Backplane Adapter 8-Position HVAB Plug 6 7 8 NI 4060 for PCI SH9MD-9MD Cable HV8-BAN4 Cable Figure 1-2. 4-Slot Single-Chassis Installation SCXI-1127/1128 User Manual 1-6 ni.
Chapter 1 1 2 Installing and Configuring the SCXI-1127/1128 4 3 AB0+ AB0– AB2+ AB2– 5 6 7 1 2 2-Slot HVAB-Backplane Adapter 8-Position HVAB Plug 3 4 1-Slot HVAB-Backplane Adapter HV8-BAN4 Cable 5 6 7 NI 4060 for PCI SH9MD-9MD Cable 4-Slot SCXI Chassis Figure 1-3. 4-Slot Configuration Parts Locator Diagram 1. Install the 2-slot HVAB-backplane adapter behind slots 3 and 4. 2. Install additional 1-slot HVAB-backplane adapters behind slots 1 and 2 if needed. 3.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Single 12-Slot Chassis Configuration Refer to Figures 1-4 and 1-5 to make connections in the single 12-slot chassis configuration. 1 2 3 4 5 6 7 8 9 1 2 3 SCXI-1127/1128 Module 12-Slot SCXI Chassis 2-Slot HVAB-Backplane Adapter 4 5 6 1-Slot HVAB-Backplane Adapter 8-Position HVAB Plug NI 4060 for PCI 7 8 9 SH9MD-9MD Cable HV8-BAN4 Cable 8-Slot HVAB-Backplane Adapter Figure 1-4.
Chapter 1 1 2 3 4 Installing and Configuring the SCXI-1127/1128 5 AB0+ AB0– AB2+ AB2– 6 7 8 1 2 3 8-Slot HVAB-Backplane Adapter 4 HV8-BAN4 Cable 5 8-Position HVAB Plug 6 2-Slot HVAB-Backplane Adapter 1-Slot HVAB-Backplane Adapter NI 4060 for PCI 7 8 SH9MD-9MD Cable 12-Slot SCXI Chassis Figure 1-5. 12-Slot Configuration Parts Locator Diagram 1. Install the 8-slot HVAB-backplane adapter behind slots 5 through 12. 2.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Connecting the SCXI-1127/1128 to the DMM in a Multichassis System The following sections describe how to configure the following multichassis configurations: • 4-slot and 4-slot multichassis configuration • 4-slot and 12-slot multichassis configuration • 12-slot and 12-slot multichassis configuration You can also create larger configurations.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Refer to Figure 1-6 to set up this multichassis configuration. 1 2 4 3 AB0+ AB0– AB2+ AB2– 5 6 10 9 8 7 1 2 3 4 2-Slot HVAB-Backplane Adapter 8-Position HVAB Plug 1-Slot HVAB-Backplane Adapter HV8-BAN4 Cable 5 6 7 NI 4060 for PCI SH9MD-9MD Cable 4-Slot SCXI Chassis 8 SH9MD-9MD Cable 9 HV8-HV8 Cable 10 4-Slot SCXI Chassis Figure 1-6. 4-Slot to 4-Slot Multichassis Configuration Parts Locator Diagram 1.
Chapter 1 Installing and Configuring the SCXI-1127/1128 2. Connect the HV8-HV8 cable from the first chassis, normally the connector behind slot 1, to the HVAB connector (behind slot 4) of the next chassis. 3. Connect the SH9MD-9MD cable from the AUX OUT connector of the first chassis to the AUX IN connector of the next chassis. 4. Repeat steps 1 through 3 for each additional chassis. Notes An SCXI-1127/1128 is required in slot 4 to establish communications with the chassis.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Refer to Figure 1-7 to set up this multichassis configuration. 1 2 3 AB0+ AB0– AB2+ AB2– 4 5 6 11 10 9 8 1 2 3 4 2-Slot HVAB-Backplane Adapter 1-Slot HVAB-Backplane Adapter HV8-BAN4 Cable NI 4060 for PCI 5 6 7 8 7 SH9MD-9MD Cable 9 SH9MD-9MD Cable 8-Position HVAB Plug 10 HV8-HV8 Cable 8-Slot HVAB-Backplane Adapter 11 4-Slot SCXI Chassis 12-Slot SCXI Chassis Figure 1-7.
Chapter 1 Installing and Configuring the SCXI-1127/1128 1. Install the HVAB-backplane adapters and jumper blocks in the 12-slot chassis as described in steps 1 through 3 in Single 12-Slot Chassis Configuration. 2. Connect the HV8-HV8 cable from the first chassis, normally the connector behind slot 1, to the HVAB connector (behind slot 12) of the next chassis. 3. Connect the SH9MD-9MD cable from the AUX OUT connector of the first chassis to the AUX IN connector (behind slot 5) of the next chassis. 4.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Refer to Figure 1-8 to set up this multichassis configuration. 1 2 3 4 5 AB0+ AB0– AB2+ AB2– 6 11 7 8 9 10 1 2 3 4 8-Slot HVAB-Backplane Adapter HV8-BAN4 Cable 8-Position HVAB Plug 2-Slot HVAB-Backplane Adapter 5 6 7 8 1-Slot HVAB-Backplane Adapter NI 4060 for PCI SH9MD-9MD Cable 12-Slot SCXI Chassis 9 HV8-HV8 Cable 10 12-Slot SCXI Chassis 11 SH9MD-9MD Cable Figure 1-8.
Chapter 1 Installing and Configuring the SCXI-1127/1128 Notes Do not connect the SH9MD-9MD cable to the 2-slot HVAB-backplane adapter. An SCXI-1127/1128 is required in slot 12 of each 12-slot chassis to establish communications with all the chassis in the system. If slot 12 is empty, the chassis will not operate. It is this module that you must specify in MAX as the module cabled to the DMM.
Chapter 1 Installing and Configuring the SCXI-1127/1128 5. Connect the HV8-BAN4 cable from the DMM to the HVAB connector behind SCXI slot 4. 6. Connect the SH9MD-9MD cable from the DMM to the AUX IN connector. 7. You can install any additional SCXI-1127/1128 modules in any slot that has an HVAB-backplane adapter behind it. DMM in PXI Slot 8 Configuration To install your DMM in PXI slot 8, follow these steps: Note 1. Install your DMM in PXI slot 8. 2.
Chapter 1 Installing and Configuring the SCXI-1127/1128 DMM in PXI Slots 1 through 3 Configuration To install your DMM in PXI slots 1 through 3, follow these steps: 1. Install your DMM in any one of the PXI slots 1 through 3. 2. In the SCXI subsystem, install the 2-slot HVAB-backplane adapter behind SCXI slots 3 and 4. 3. Install additional 1-slot HVAB-backplane adapters behind SCXI slots 1 and 2 if needed. 4. Install the 8-position HVAB plugs to connect the HVAB-backplane adapters as needed. 5.
Chapter 1 • Installing and Configuring the SCXI-1127/1128 At least one other SCXI module other than the SCXI-1127/1128, installed in the chassis Consult the documentation for your SCXI chassis and other SCXI modules for additional instructions and warnings. Any non-SCXI-1127/1128 modules should already be installed according to their installation instructions.
Chapter 1 Installing and Configuring the SCXI-1127/1128 3. Attach the other end of the DAQ cable to the National Instruments DAQ device. 4. Check the installation. 5. Turn on the SCXI chassis. 6. Turn on the computer or reconnect it to your chassis. If you already have the appropriate software installed, you are ready to configure the SCXI-1127/1128 via an SCXI module other than the SCXI-1127/1128 module.
Chapter 1 – SH9MD-9MD cable – 8-position HVAB plug – HV8-BAN4 cable Installing and Configuring the SCXI-1127/1128 • External DMM (if needed) • BAN2-WIRE kit (two kits needed for 4-wire), if not using the HV8-BAN4 cable • Cable or wires to connect the handshaking lines to the SCXI-1127/1128 • 1/8 in. flathead screwdriver Consult the documentation for your SCXI chassis and other SCXI modules for additional instructions and warnings.
Chapter 1 Installing and Configuring the SCXI-1127/1128 For the system to function properly, it must be controlled by a DAQ device or NI 4021 switch controller, or be a 2000 Series SCXI chassis. Note Configuring and Self-Test Run Measurement & Automation Explorer (MAX) to configure and test your SCXI-1127/1128. If you need help during the configuration process, open the Measurement & Automation Help file by selecting Help»Help Topics. 1. Run MAX by double-clicking the icon on your desktop. 2.
Chapter 1 Installing and Configuring the SCXI-1127/1128 2. You will see the chassis selected in the list. Display the list of modules in the chassis by clicking the + next to the Chassis icon. 3. Right-click the module you want to configure and select Properties. You will be presented with tabs containing attributes for different properties of the module. You can select any tab to see and/or change any attributes.
Chapter 1 Installing and Configuring the SCXI-1127/1128 To remove a module or chassis, right-click the chassis or module you want to remove and select Delete. To test the chassis configuration, right-click the chassis and select Test. Safety Information The following cautions contain important safety information concerning hazardous voltages. Cautions You must insulate all of your signal connections appropriately to the highest available voltage with which the SCXI-1127/1128 may come in contact.
Chapter 1 Installing and Configuring the SCXI-1127/1128 National Instruments for service and repair to ensure that its safety features are not compromised. When using the terminal block with high common-mode voltages, you must insulate your signal wires appropriately. National Instruments is not liable for any damages or injuries resulting from inadequate signal wire insulation.
Using the SCXI-1127/1128 2 This chapter discusses in detail the operation of the SCXI-1127/1128. There are two major modes of operation: multiplexer and matrix. A third mode of operation, independent mode, allows you to access advanced features of the SCXI-1127/1128. Operating as a Multiplexer/Scanner You can configure the SCXI-1127/1128 to operate as a multiplexer/scanner.
Chapter 2 Using the SCXI-1127/1128 The SCXI-1331 terminal block consists of a shielded board with 84 screw terminals for easy connection to the SCXI-1127/1128 input connector. The SCXI-1331 is shown in Figure 2-1.
Chapter 2 Using the SCXI-1127/1128 The SCXI-1127/1128 contains a safety interlocking mechanism that prevents high voltages from appearing on the input connector when a terminal block is not present. However, when a SCXI-1331 or SCXI-1332 is plugged into the front of the SCXI-1127/1128, the module detects its presence and allows the module to close relays.
Chapter 2 Using the SCXI-1127/1128 Figure 2-3 shows an example of a 2-wire configuration using the SCXI-1331 terminal block. The diagram shows the 2-wire terminal block connections for channels 2, 5, 24, and 27. Channel 2 measures a voltage source (V1). The positive terminal of channel 2 is labeled +2 with the negative channel labeled –2. The output of the multiplexer is available through the OUT0 bus. OUT0± – Multiplexer Output + V1 + – SCXI-1127 R1 R2 V2 Thermocouple Figure 2-3.
Chapter 2 Using the SCXI-1127/1128 1-Wire Channel Scanning Configuration The SCXI-1127/1128 has 64, 1-wire channels in the multiplexer mode that are available through the SCXI-1331 terminal block. Figure 2-4 shows the SCXI-1127/1128 configured as a 64-to-1, 1-wire multiplexer. A 1-wire configuration provides a high channel count because all input signals have the same reference.
Chapter 2 Using the SCXI-1127/1128 Multiplexer Output OUT0± – + R1 – + SCXI-1127 V1 V2 + – Figure 2-5. 1-Wire Wiring Diagram Both channel 24 (V1) and 59 (V2) are measuring voltage sources. The positive terminal of these sources go to screw terminals labeled 24 and 59 respectively. The negative terminals or the common reference for the voltage source is wired to the 1_WIRE_LO_REF screw terminals. The output of the multiplexer is available through the OUT0 bus.
Chapter 2 Using the SCXI-1127/1128 Out0– Out0+ 0A+ 0A– 16-to-1 Multiplexer AB0+ 15A+ 15A– AB0– EXCITATION Multiplexer Out2– Out2+ HVAB Backplane AB0 Switch AB2+ AB2– 0B+ 0B– 16-to-1 Multiplexer AB2 Switch 15B+ 15B– SENSE Multiplexer Figure 2-6. 4-Wire Block Diagram When used with a DMM for 4-wire ohms measurement, the upper differential multiplexer provides the excitation source for the 4-wire channel being scanned.
Chapter 2 Using the SCXI-1127/1128 6A ± Excitation for Four-Wire Channel 6 6B ± Sense for Four-Wire Channel 6 – Sense Output Excitation Input + – + I Iex + SCXI-1127 R2 – – R2 + Iex Figure 2-7. 4-Wire Wiring Diagram On power up, the AB0 and AB2 switches are open, disconnecting the SCXI-1127/1128 from the high-voltage bus. If you are using this module with a high-voltage backplane, you need to close the AB0 and AB2 switches to connect the EXCITATION and SENSE commons to the HVAB backplane.
Chapter 2 Using the SCXI-1127/1128 negative screw terminals and sensed via 1B positive and negative screw terminals. Note OUT0± and OUT2± are also referred to as COM0± in a 4-wire configuration. 4-Wire versus 2-Wire Resistance Measurement The primary advantage of using a 4-wire configuration is that it has greater accuracy than a 2-wire configuration while making resistance measurements. Figure 2-8 shows signal connections for a 2-wire resistance measurement of a resistor R1.
Chapter 2 Using the SCXI-1127/1128 current and the other for sensing the voltage developed across the resistor, as shown in Figure 2-9. 4-Wire Measurement RP IEX VR1 RP IP~0 VSENSE+ R1 RP IP~0 VSENSE– RP IEX Figure 2-9. Signal Connections for a 4-Wire Resistance Measurement Since ideally the impedance of the voltmeter is infinite, very little or no current passes through the sense leads of the voltmeter.
Chapter 2 Using the SCXI-1127/1128 – V2 + 1-Wire Connection V1 2-Wire Connection 4-Wire Connection + – SCXI-1127 – R1 + Iex Figure 2-10. Mixed Mode Scanning with an SCXI-1331 You can scan the channels in any sequence you want. You can connect more than one SCXI-1127/1128 module together using the HVAB-backplane adapter from the SCXI-1357/1358 kits to expand the channel count of the system. When combining different modes in one module it is important to use the channels efficiently.
Chapter 2 Using the SCXI-1127/1128 SCXI-1127/1128. In its simplest form, hardware-timed scanning uses one triggering signal to advance the multiplexer to the next channel in the scan. This is called synchronous scanning. When using a DMM with the SCXI-1127/1128, synchronous mode is the only mode in which the DMM and the SCXI-1127/1128 operate. Note Another hardware-timed scanning method is called handshaking.
Chapter 2 Using the SCXI-1127/1128 Reset The channel scan list is downloaded to SCXI-1127/1128. The first channel in the scan list is selected. The SCXI-1127/1128 is now armed to respond to triggers on EXT_TRIG_IN. Stay at the selected channel in the scan list. EXT_TRIG_IN pulsed? No Yes Is the SCXI-1127/1128 armed? No Yes Is the SCXI-1127/1128 at the end of the scan list? Yes Return to the top of the scan list and select the first channel in the list.
Chapter 2 Using the SCXI-1127/1128 Hardware-Timed Scanning Using a DMM When using a DMM with the SCXI-1127/1128, synchronous mode is the only mode in which the DMM and the SCXI-1127/1128 operate. The DMM issues a trigger to advance the multiplexer at regular intervals. The DMM and the software guarantee that the switch has fully settled before the next measurement is taken. The module that connects directly to the digital connector on the HVAB-backplane adapter is referred to as the cabled module.
Chapter 2 Using the SCXI-1127/1128 The module to which you connected your external DMM trigger signals is referred to as the cabled module. If you add additional SCXI-1127/1128 modules to your system, it is not necessary to cable the VMC signal to each module. You can bus the VMC signal onto the SCXI backplane (Trig 0), allowing other modules to be triggered as shown in Figure 2-13.
Chapter 2 Using the SCXI-1127/1128 module. You can bus the VMC onto the SCXI backplane (Trig 0), allowing other modules to be triggered as shown in Figure 2-14. You must daisy-chain the SCANADVD trigger from one module to another. SCANADVD To DMM EXT_TRIG_IN From DMM VMC Cabled SCXI-1127/1128 SCXI-1127/1128 SCXI-1127/1128 Backplane Connector Digital Communication Connector HVAB Connector Trig 0 (Backplane) Figure 2-14.
Chapter 2 Using the SCXI-1127/1128 Software Scanning Unlike hardware scanning, software scanning does not use hardware-generated triggers. In software scanning, a list of channels kept by the software is scanned by selecting the desired channel on the SCXI-1127/1128 and making the required measurement. Refer to the NI-SWITCH documentation for more information on software scanning.
Chapter 2 Using the SCXI-1127/1128 Thermocouple V1 SCXI-1127/1128 Thermistor R2 RTD R1 + Iex Figure 2-16. Temperature Measurement Wiring Diagram The SCXI-1331 contains a cold-junction temperature sensor (CJS). This sensor is a special channel on the SCXI-1127/1128 dedicated to measuring the ambient temperature of the terminal block. This channel is always scanned as a 2-wire channel. Including a CJS channel in the scan list is optional.
Chapter 2 Using the SCXI-1127/1128 NI-DAQ, use the Thermistor_Convert function. The VI takes the output voltage of the temperature sensor, the reference voltage, and the precision resistance and returns the thermistor temperature. Alternatively, you can use the following formulas: T(°C) = TK – 273.15 where TK is the temperature in Kelvin, 1 T K = ------------------------------------------------------------3 [ a + b ( ln R T ) + c ( ln R T ) ] where a = 1.295361 × 10 –3 b = 2.343159 × 10 –4 c = 1.
Chapter 2 Using the SCXI-1127/1128 the best accuracy, while 1-wire provides the maximum channel count. Use the 4-wire configuration to eliminate the effects of lead resistance on the measurement. Since the lead resistance is typically small when compared with the thermistor range, the impact of the lead resistance error is smaller than you have in an RTD measurement. See the 4-Wire versus 2-Wire Resistance Measurement section for more information.
Chapter 2 Using the SCXI-1127/1128 Figure 2-18 shows an example of the SCXI-1331 and SCXI-1127/1128 configured as a 1 × 32, 2-wire matrix. The diagram shows the 2-wire terminal block connections for channels 3, 15, 27 and OUT0. You can use this configuration to connect VSOURCE to one or all of the device under test (DUT) channels. VSOURCE – + To Device Under Test #1 + To Device Under Test #2 + To Device Under Test #3 + – SCXI-1127 – – Figure 2-18.
Chapter 2 Using the SCXI-1127/1128 6 1 5 2 4 3 1 1 2 Column Expansion Bus Row Expansion Bus 3 4 Row Connections Column Connections 5 6 Cable Strain-Relief Safety Ground Solder Lug Figure 2-19. SCXI-1332 Terminal Block The SCXI-1127/1128 installed with the SCXI-1332 provides you with an 4 × 8 matrix without any extra wiring except for hooking up your signals to the columns and rows of the matrix.
Chapter 2 Using the SCXI-1127/1128 supply output voltage and to measure the load resistors. A simple test can consist of first measuring the values of the resistances while they are not connected to the power supply, and then monitoring the output voltage as different resistors are connected. Figure 2-21 shows a schematic of this application. + Power Supply – Load Resistors SCXI-1127 + DMM – Figure 2-20.
Chapter 2 Using the SCXI-1127/1128 Load Resistors Power Supply + r0 – + DMM r1 – r2 r3 c0 c1 c2 c3 c4 c5 c6 c7 Figure 2-21. SCXI-1332 Connected to an SCXI-1127/1128 Schematic Matrix Expansion You can build matrices larger than 4 × 8 by using multiple SCXI-1127/1128 modules. You can build these larger matrices using row and column expansion of the 4 × 8 matrix. An example of row expansion is an 8 × 8 matrix. A 4 × 16 matrix is an example of a column expansion.
Chapter 2 Using the SCXI-1127/1128 1 2 2 3 1 SCXI-1127/1332 #1 2 Matrix Expansion Cables 3 SCXI-1127/1332 #2 Figure 2-22.
Chapter 2 Using the SCXI-1127/1128 SCXI-1127/SCXI-1332 #1 R0 R1 R2 Cable #2 Cable #1 R3 Terminal Block Boundary R4 (R0) R5 (R1) R6 (R2) C7 C6 C5 C4 C3 C2 C1 C0 R7 (R3) SCXI-1127/SCXI-1332 #2 Figure 2-23. 8 × 8 Matrix Schematic To make a larger matrix, such as a 8 × 16 matrix, you must make both column and row expansions. Follow these instructions to build a larger matrix: 1.
Chapter 2 2. Using the SCXI-1127/1128 Expand the rows to the target number, 8 in this case, by connecting the columns of the appropriate number of 4 × 16 matrix blocks, two in this case, using matrix expansion cables. Figure 2-24 shows four SCXI-1332s connected to form a 8 × 16 matrix. 1 2 5 1 1 1 1 3 4 1 1 2 Matrix Expansion Cables SCXI-1127/1332 #3 3 4 SCXI-1127/1332 #4 SCXI-1127/1332 #2 5 SCXI-1127/1332 #1 Figure 2-24.
Chapter 2 Using the SCXI-1127/1128 Figure 2-25 shows the schematic of the 8 × 16 matrix shown in Figure 2-24. SCXI-1127/SCXI-1332 #1 Terminal Block Boundary SCXI-1127/SCXI-1332 #3 R0 R1 Cable #6 R2 Cable #4 Cable #2 Cable #3 Cable #5 R3 R4 (R0) R5 (R1) Cable #1 R6 (R2) C15 (C7) C14 (C6) C13 (C5) C12 (C4) C11 (C3) C10 (C2) SCXI-1127/SCXI-1332 #2 C9 (C1) C8 (C0) C7 C6 C5 C4 C3 C2 C1 C0 R7 (R3) SCXI-1127/SCXI-1332 #4 Figure 2-25.
Chapter 2 Using the SCXI-1127/1128 Independent Mode The SCXI-1127/1128 powers up in independent mode. In this mode, you can close or open any switch on the module via NI-SWITCH to the SCXI-1127/1128. All software-controllable switches are shown in Figure 2-26. You can use the independent mode for advanced switching or scanning needs. You can control these switches using NI-SWITCH.
SCXI-1127/1128 User Manual 2-30 OUT3 OUT1 OUT2 OUT0 Front Signal Connector Relay Channel Bank 2 CH24+/– – CH31+/– CH+ (24:31) CH– (24:31) Relay Channel Bank 4 CH16+/– – CH23+/– Relay Channel Bank 3 CH8+/– – CH15+/– CH+ (8:15) CH– (8:15) CJS Relay Relay Channel Bank 1 CH0+/– – CH7+/– CH+ (16:23) CH– (16:23) CH+ (0:31) CH– (0:31) 2 CH+ (0:7) CH– (0:7) CJTEMP+, CJTEMP– AISENSE 8 7 6 5 9 BC23 9 9 BC01 COM0+ COM3– COM3+ COM2– COM2+ COM1– COM1+ BC02 COM0– 9 AISENSE One-WI
A Specifications This appendix lists the specifications for the SCXI-1127/1128 modules. These specifications are typical at 25 °C unless otherwise noted. SCXI-1127 Input Characteristics Number of relays available as channels ............................................. 32 Common-mode voltage Channel to channel.......................... 300 Vrms or DC Channel to earth .............................. 300 Vrms or DC Maximum allowed voltage—differential mode or single-ended AC ...............................
Appendix A Specifications for SCXI-1127 Channel to channel crosstalk ..................50 Ω termination 10 kHz .............................................≤ –70 dB 100 kHz ...........................................≤ –57.79 dB 1 MHz..............................................≤ –53.31 dB 5 MHz..............................................≤ –41.47 dB 11 MHz............................................≤ –27.23 dB Dynamic Characteristics Maximum operating speed .....................
Appendix A Specifications for SCXI-1127 Physical Dimensions............................................. 3.0 by 17.2 by 20.3 cm (1.2 by 6.9 by 8.0 in.) Environment Operating temperature ..........................0 to 50 °C Storage temperature..............................–20 to 70 °C Relative humidity ................................... 10% to 90% noncondensing Electromagnetic compatibility (EMC) emissions................................................
Appendix A Specifications for SCXI-1128 SCXI-1128 Input Characteristics Number of relays available as channels ..............................................32 Common-mode voltage Channel to channel ..........................300 Vrms or DC Channel to earth...............................300 Vrms or DC Maximum allowed voltage—differential mode or single-ended AC....................................................250 Vrms DC....................................................
Appendix A Specifications for SCXI-1128 Dynamic Characteristics Maximum operating speed..................... 1200 cycles/s Relay operate time (at 20 °C) ................ 0.25 ms typical, 0.5 ms max Relay release time (at 20 °C) ................. 0.08 ms typical, 0.2 ms max Trigger Characteristics Scanner advanced pulsewidth ................ 1.1 µs External trigger input pulsewidth........... 500 ns (min) Stability Recommended warm-up time ................ 5 minutes Physical Dimensions..................
Appendix A Specifications for SCXI-1128 Pollution Degree 2 Indoor use only SCXI-1127/1128 User Manual A-6 ni.
B Accessories This appendix lists various National Instruments products you can use with your SCXI-1127/1128 module. • The SCXI-1331 terminal block has screw terminal connections for all channels, bank commons, analog bus, and trigger signals. You can use this module for multiplexer switching applications. The terminal block has a temperature sensor that is used for thermocouple cold-junction compensation. • The SCXI-1332 terminal block converts the switch card to a 4 × 8, 2-wire matrix configuration.
Appendix B Accessories Contact National Instruments for more specific information about these products. SCXI-1127/1128 User Manual B-2 ni.
C Customizing Your Module This appendix describes how to customize your SCXI-1127/1128 module for current-loop receiving. The SCXI-1127/1128 modules have plated through holes for transforming individual channels to current-to-voltage converters. National Instruments offers a process-current pack of four 249 Ω, 0.1%, 5 ppm, 0.25 W resistors. The reference designator format for the current-loop resistors is such that input channel x corresponds to the resistor reference designator RCLx.
Appendix C Customizing Your Module 1. Ground yourself via a grounding strap or a ground connected to your SCXI chassis. Properly grounding yourself prevents damage to your SCXI module from electrostatic discharge. 2. Remove the grounding screw from the top cover. 3. Snap out the top cover of the shield by placing a screwdriver in the groove at the bottom of the module and pushing down. 4. Remove the rear panel by unscrewing the two remaining screws. 5. Slide the module out of its enclosure. 6.
D SCXI-1127/1128 Front Connector This appendix contains connector diagrams for the SCXI-1127/1128 switch cards. The diagrams also show the signal names that are used when the modules are in 2-wire mode, 1-wire mode, 4-wire mode, and 4 × 8 matrix configuration. When you connect a custom terminal block or cable it is important that you incorporate the safety interlock scheme into the terminal block/cable. You do this by connecting the +5 V (ISO)_HVAB_EN signal to the +5 V (ISO) signal.
Appendix D SCXI-1127/1128 Front Connector Pin Number Signal Name Column A B C CH2+ 32 31 CH2– 30 CH5+ 29 CH5– 28 CH8+ 27 CH8– 26 CH11+ 25 CH11– 24 CH14+ 23 CH14– 22 CH17+ 21 CH17– 20 CH20+ 19 CH20– 18 CH23+ 17 CH23– 16 CH26+ 15 CH26– 14 CH29+ 13 CH29– 12 OUT0+ 11 OUT0– 10 OUT3+ 9 OUT3– 8 CJS0– 7 +5 V (ISO) 6 NC 5 NC 4 NC 3 +5 V (Non-Isolated) 2 GND (Non-Isolated) 1 SCANADVD Signal Name CH0– CH0+ CH1– CH1+ CH3– CH3+ CH4– CH4+ CH6– CH6+ CH7– C
Appendix D Pin Number Signal Name SCXI-1127/1128 Front Connector Column A B C 32 CH2 31 CH34 30 CH5 29 CH37 28 CH8 27 CH40 26 CH11 25 CH43 24 CH14 23 CH46 22 CH17 21 CH49 20 CH20 19 CH52 18 CH23 17 CH55 16 CH26 15 CH58 14 CH29 13 CH61 12 OUT0+ 11 OUT0– 10 OUT3+ (CH24-CH31) 9 OUT3– (CH56-CH63) 8 CJS– 7 +5 V (ISO) 6 NC 5 NC 4 NC 3 +5 V (Non-Isolated) 2 GND (Non-Isolated) 1 SCANADVD Signal Name CH32 CH0 CH33 CH1 CH35 CH3 CH36 CH4 CH38 CH6 CH3
Appendix D SCXI-1127/1128 Front Connector Pin Number Signal Name Column A B C CH2A+ 32 31 CH2A– 30 CH5A+ 29 CH5A– 28 CH8A+ 27 CH8A– 26 CH11A+ 25 CH11A– 24 CH14A+ 23 CH14A– 22 CH1B+ 21 CH1B– 20 CH4B+ 19 CH4B– 18 CH7B+ 17 CH7B– 16 CH10B+ 15 CH10B– 14 CH13B+ 13 CH13B– 12 OUT0A+ 11 OUT0A– 10 OUT1B+ 9 OUT1B– 8 CJS– 7 +5 V (ISO) 6 NC 5 NC 4 NC 3 +5 V (Non-Isolated) 2 GND (Non-Isolated) 1 SCANADVD Signal Name CH0A– CH0A+ CH1A– CH1A+ CH3A– CH3A+ CH
Appendix D Pin Number Signal Name Column A B C C2+ 32 SCXI-1127/1128 Front Connector 31 C2– 30 C5+ 29 C5– 28 C0+ 27 C0– 26 C3+ 25 C3– 24 C6+ 23 C6– 22 C1+ 21 C1– 20 C4+ 19 C4– 18 C7+ 17 C7– 16 C2+ 15 C2– 14 C5+ 13 C5– 12 R0+ 11 R0– 10 R3+ 9 R3– 8 CJS– 7 +5 V (ISO) 6 NC 5 NC 4 NC 3 +5 V (Non-Isolated) 2 GND (Non-Isolated) 1 SCANADVD Signal Name C0– C0+ C1– C1+ C3– C3+ C4– C4+ C6– C6+ C7– C7+ C1– C1+ C2– C2+ C4– C4+ C5– C5+ C7– C7+ C0– C0+ C2
Appendix D SCXI-1127/1128 Front Connector Table D-1.
E Common Questions This appendix addresses common questions you may have while using your SCXI-1127/1128 module. How fast can I scan with the SCXI-1127/1128 module? The fastest scan rate for the SCXI-1127 is 100 scans/s, and the fastest scan rate for the SCXI-1128 is 1000 scans/s. Typically, when using a DMM to make accurate measurements, the DMM requires hundreds of milliseconds. Consequently, the DMM becomes the limiting factor in determining the scan rate.
Appendix E Common Questions • If you use the SCXI-1127/1128 to initiate the scan, make sure the DMM is waiting for a trigger before enabling scanning on the SCXI-1127/1128. • If you use the DMM to initiate the scan, enable scanning on the SCXI-1127/1128 before configuring the DMM to start taking measurements. This is the recommended method for scanning. • Be sure to check the return codes of the NI-SWITCH operation to ensure that there are no errors (negative values) or warnings (positive values).
Appendix E Common Questions behind slots 3 and 4 you have connected the rows between slot 3 and 4 which creates a 4 × 16 matrix. Now install the two 1-slot adapters behind slots 1 and 2. Connect the two 1-slot adapters together with an 8-position HVAB plug. Do not connect the 2-slot HVAB-backplane adapter to the 1-slot adapters as this would create a 4 × 32 matrix. You now have created two independent 4 × 16 matrices.
Technical Support Resources F Web Support National Instruments Web support is your first stop for help in solving installation, configuration, and application problems and questions. Online problem-solving and diagnostic resources include frequently asked questions, knowledge bases, product-specific troubleshooting wizards, manuals, drivers, software updates, and more. Web support is available through the Technical Support section of ni.com NI Developer Zone The NI Developer Zone at ni.
Appendix F Technical Support Resources Worldwide Support National Instruments has offices located around the world to help address your support needs. You can access our branch office Web sites from the Worldwide Offices section of ni.com. Branch office Web sites provide up-to-date contact information, support phone numbers, e-mail addresses, and current events.
Glossary Prefix Meanings Value n- nano- 10 –9 µ- micro- 10 – 6 m- milli- 10 –3 k- kilo- 10 3 M- mega- 10 6 G- giga- 10 9 Symbols ° degrees Ω ohms % percent ± plus or minus A A amperes AC alternating current ADE application development environment ANSI American National Standards Institute B bus the group of conductors that interconnect individual circuitry in a computer. Typically, a bus is the expansion vehicle to which I/O or other devices are connected.
Glossary C C Celsius channel pin or wire lead on the multiplexer to which you apply or from which you read the analog or digital signal. Signals can be single-ended or differential. CJS cold junction sensor cold-junction compensation a method of compensating for inaccuracies in thermocouple circuits contact bounce the intermittent switching that occurs when the movable metal parts of a relay make or break contact D DC direct current debounced indicates when the contact bounce has ended.
Glossary H handshaking the use of two trigger lines between two instruments, such as a switch and a DMM, to synchronize their actions hardware-timed scanning the measurement instrument communicates via digital trigger signals HVAB high-voltage analog bus Hz hertz—the number of scans read or updates written per second I in.
Glossary R random scanning scanning the channels in a mux in any order relay a switch that connects or disconnects the signal to a common through the physical movement of a metal arm RMA Return Material Authorization rms root mean square—the square root of the average value of the square of the instantaneous signal amplitude; a measure of signal amplitude RTD resistance temperature detector—a metallic probe that measures temperature based upon its coefficient of resistivity S s seconds scan th
Glossary soft front panel a graphical program included with NI-SWITCH that you can use to interactively control the switch software scanning a method by which channels are selected through the software synchronous scanning hardware-timed scanning uses one triggering signal to advance the multiplexer to the next channel in the scan T TBX Terminal Block eXtension terminal block an accessory containing wire connection points, typically screw terminals thermistor a semiconductor sensor that exhibits
Glossary W W watts wire data path between nodes SCXI-1127/1128 User Manual G-6 ni.
Index Numbers 32x1 matrix configuration, 2-20 to 2-21 1-wire channel scanning configuration, 2-5 to 2-6 block diagram, 2-5 wiring diagram, 2-6 1_WIRE_LO_REF signal description (table), D-6 one-wire channel scanning configuration, 2-5 to 2-6 2-wire channel scanning configuration, 2-3 to 2-4 block diagram, 2-3 wiring diagram, 2-4 2x4 one-wire matrix configuration (figure), 2-20 4-wire channel scanning configuration, 2-6 to 2-9 block diagram, 2-7 wiring diagram, 2-8 4-wire versus 2-wire resistance measuremen
Index D H DAQ devices accessing SCXI-1127/1128 through other SCXI modules, 1-18 to 1-20 PXI-1010 chassis, 1-20 PXI-1011 chassis, 1-20 DMM (digital multimeter). See external DMMs; NI DMM. dynamic characteristics SCXI-1127, A-2 SCXI-1128, A-5 handshaking scanning mode, 2-15 to 2-16 hardware installation. See installation.
Index 8x16 matrix parts locator diagram (figure), 2-27 8x16 matrix schematic (figure), 2-28 Measurement & Automation utility, 1-22 mixed mode scanning configuration, 2-10 to 2-11 multiple-chassis system, installing. See installation.
Index O temperature measurements, 2-17 to 2-20 RTD measurements, 2-19 thermistor measurements, 2-19 to 2-20 thermocouple measurements, 2-17 to 2-19 OUT<0..1>A± signal (table), D-6 OUT<0..1>B± signal (table), D-6 OUT<0..3>signal (table), D-6 OUT0± signal (table), D-6 P N physical specifications SCXI-1127, A-3 SCXI-1128, A-5 pin assignments. See front connector.
Index transfer characteristics, A-1 to A-2 trigger characteristics, A-2 SCXI-1128 dynamic characteristics, A-5 environment, A-5 input characteristics, A-4 physical, A-5 safety, A-3 to A-6 stability, A-5 transfer characteristics, A-4 trigger characteristics, A-5 stability specifications SCXI-1127, A-2 SCXI-1128, A-5 synchronous scanning mode, 2-14 to 2-15 system integration, by National Instruments, F-1 SCANADVD signal description (table), D-6 handshaking scanning, 2-15 to 2-16 hardware timed scanning, 2-1
