PCI-1720 4-channel Isolated D/A Output Card User's manual
Copyright This documentation and the software included with this product are copyrighted 1999 by Advantech Co., Ltd. All rights are reserved. Advantech Co., Ltd. reserves the right to make improvements in the products described in this manual at any time without notice. No part of this manual may be reproduced, copied, translated or transmitted in any form or by any means without the prior written permission of Advantech Co., Ltd. Information provided in this manual is intended to be accurate and reliable.
Contents CHAPTER 1 General Information ......................... 1 1.1 Introduction ......................................................... 2 1.2 Features ............................................................... 2 1.3 Applications ......................................................... 3 1.4 Specifications....................................................... 3 1.5 Block Diagram .................................................... 5 CHAPTER 2 Installation ........................................
.2.3 Synchronized Output Prompt Register ....................... 21 4.2.4 Synchronized Output Control Bit ................................. 21 4.3 Unipolar and Bipolar Binary Code Tables .... 22 CHAPTER 5 Signal Connections ......................... 23 5.1 Overview ............................................................ 24 5.2 D/A Voltage Output Connections .................... 24 5.3 Current Sink Connections ............................... 25 5.4 Current Sink Load and Power Supply ...........
CHAPTER 1 General Information
1.1 Introduction The PCI-1720 is an isolated digital-to-analog output card for the PCI bus. It provides four 12-bit analog output channels with isolation protection of 2500 VDC between the outputs and the PCI bus. This is ideal for industrial applications where high-voltage protection is required. Keeping the Output Settings and Values after System Reset Users can set the four outputs independently to different ranges: 0 to +5 V, 0 to +10 V, ±5 V, ±10 V, 0 to 20 mA (sink) or 4 to 20 mA (sink).
1.3 Applications * Process control * Programmable voltage source * Programmable current sink * Servo control 1.4 Specifications D/A Output * Channels: 4 isolated D/A channels * Resolution: 12 bits * Output ranges: Unipolar: 0 ~ +5 V, 0 ~ +10 V Bipolar: ±5 V, ±10 V Current loop (sink): 0 ~ 20 mA, 4 ~ 20 mA * Throughput: 500 kHz * Accuracy: ±0.
Power consumption * +5 V @ 350 mA (typical), 500mA (Max.) * +12V @ 200 mA (typical), 350mA (Max.) Physical * Connector: 37-pin D-type connector * Dimensions: 175 x 100 mm (6.9" x 3.
1.
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CHAPTER 2 Installation Chapter 2 Installation 7
2.1 Initial Inspection Before installing the PCI-1720, check the card for visible damage. We have carefully inspected the card both mechanically and electrically before shipment. It should be free of marks and in perfect order upon receipt. As you unpack the PCI-1720, check it for signs of shipping damage (damaged box, scratches, dents, etc.). If it is damaged or fails to meet specifications, notify our service department or your local sales representative immediately.
2.3 Installation Instructions The PCI-1720 can be installed in any PCI slot in the computer. However, refer to the computer user's manual to avoid any mistakes and danger before you follow the installation procedure below: 1. Turn off your computer and any accessories connected to the computer. Warning! TURN OFF your computer power supply whenever you install or remove any card, or connect and disconnect cables. 2. Disconnect the power cord and any other cables from the back of the computer. 3.
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CHAPTER 3 Jumpers and I/O Connectors
The PCI-1720 is a “plug-and-play” card, i.e. the system BIOS assigns the system resources such as the base address and the interrupt number automatically. There are only 2 functions with 5 jumpers to configure to your applications requirements. The following sections offer the necessary information for setting the PCI-1720’s jumpers. You may need to refer to the figure below for help in identifying jumper locations. Figure 3-1: PCI-1720 jumper locations 3.1 Jumper Settings 3.1.
JP1 to JP4 0 ~ 20 m A 4 ~ 20 m A Figure 3-2: Jumper settings for PCI-1720’s current sink range Note!: In order to maintain accurate outputs for your field applications, it is important that you calibrate the PCI1720’s variable resistors (VRs) from time to time. Calibration instructions are provided in Appendix A. 3.1.2 Jumper JP5 Setting for the Reset State Jumper JP5 gives the PCI-1720 a new and valuable capability.
When jumper JP5 is disabled, power-off or “hot” reset results in outputs returning to their default state. JP5 K e e p s la s t s ta tu s a fte r re s e t L o a d s d e fa u lt w h ile re s e t Figure 3-3: Jumper JP5 setting for the reset state 3.2 Connector and pin assignments The PCI-1720 uses one DB-37 female connector, which is located on the card at CN1 (see Figure 3-1) and connects D/A signals to external devices. The following figure shows the pin assignments of the connector.
3.2.1 Signal Descriptions of I/O Connector Signal Name Reference Direction Description VOUT<0...3> AGND Output Analog Voltage Output Channels 0 through 3. These pins supply the voltage outputs for the analog outputs. ISINK <0...3> AGND Input Current Sink Channels 0 through 3. These pins provide the current loop sink input. +12 VOUT AGND Output +12 VDC Source. This pin is a +12 VDC power supply (80mA max.) for current loop exciting voltage. AGND - - Analog Ground.
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CHAPTER 4 Register Structure and Format
4.1 Overview The PCI-1720 is delivered with an easy-to-use 32-bit DLL driver for user programming under the Windows 95/98/NT operating system. We advise users to program the PCI-1720 using the 32-bit DLL driver provided by Advantech to avoid the complexity of low-level programming by register. The most important consideration in programming the PCI-1720 card at a register level is to understand the function of the card’s registers.
Table 4-1: PCI-1720 register format and function description Base Address + decimal 7 6 5 4 +0 D7 D6 D5 D4 Data +1 +2 D7 D6 D5 +4 D7 D6 D5 +6 D7 D6 D5 0 D2 D1 D0 D10 D9 D8 D3 D2 D1 D0 D11 D10 D9 D8 D3 D2 D1 D0 D11 D10 D9 D8 D4 +7 1 D3 D4 +5 2 D11 D4 +3 Function description R/W 3 D3 D2 D1 D0 D11 D10 D9 D8 D/A output channel 0 W D/A output channel 1 W D/A output channel 2 W D/A output channel 3 W DA3_ DA3_ DA2_ DA2_ DA1_ DA1_ DA0_ DA0_ D
D11 ~ D0 Digital to Analog data D0 is the LSB (Least Significant Bit) and D11 is the MSB (Most Significant Bit) of the D/A data. Note!: To write D/A data, write the low byte first, then write the high byte. 4.2.2 D/A Voltage Range and Polarity The read-writable register of BASE + 8 allows users to set the D/A voltage range and polarity.
4.2.3 Synchronized Output Prompt Register During normal operation, the PCI-1720 will accept digital values one at a time from the host PC, convert these values to analog values, and immediately output these analog values from the channels directed by the host PC. However, the PCI-1720 has the capability to store each analog value in its proper channel buffer as it is generated, then simultaneously output one analog value from each of its four channels on receipt of a synchronizing character.
4.3 Unipolar and Bipolar Binary Code Tables Table 4-6: Unipolar binary code table Digital Input Code MSB LSB Examples of Analog Output Voltage 1111 1111 1111 Vref (4095/4096) 1000 0000 0001 Vref (2049/4096) 1000 0000 0000 Vref (2048/4096) 0111 1111 1111 Vref (2047/4096) 0000 0000 0001 Vref (1/4096) 0000 0000 0000 Vref (0/4096) Notes: 1. Vref is the reference source voltage that you selected. Vref is +5 V or +10 V. 2. Nominal full scale is given by FS = Vref ( (4095/ 4096). 3.
CHAPTER 5 Signal Connections
5.1 Overview Making correct signal corrections is important for accurate data transmissions. Since most data acquisition applications involve some form of voltage measurement, making a sound signal connection will also protect your equipment against possible damage. This chapter shows you how to make proper signal connections to use PCI-1720. 5.2 D/A Voltage Output Connections PCI-1720 supports four channels of D/A voltage output. Only one output signal wire is used with each channel.
Internal Side External Side VO U T D /A G roun ded Lo ad AGND Figure 5-2: Grounded-load connection for D/A voltage output Internal S ide D/A E xternal S ide V OU T D iff. Load w ith G roun d AGND Figure 5-3: Differential-load connection for D/A voltage output 5.3 Current Sink Connections The PCI-1720's current loop output uses a 0 to +5 V (unipolar) voltage output as each channel’s driving source. Current drive circuits consist of a power field-effect transistor (FET).
3. Floating load with an internal +12 V power supply. These are shown in the following illustrations.
5.4 Current Sink Load and Power Supply You have to select the current sink load and power supply carefully. The current sink circuitry of the PCI-1720 is as shown below. Internal Side 0~5V or 1~5V + - External Side PD RL 0 ~ 20 m A or 4 ~ 20 m A + - 249 Ω Vs A G ND Figure 5-7: PCI-1720 current sink circuitry where VS: Power supply voltage of current sink. RL: Load of current sink. PD: Power dissipation of FET. When you determine VS and RL, three conditions must be satisfied.
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APPENDIX A Calibration Appendix A Calibration 29
A.1 Overview The PCI-1720 card uses eight variable resistors (VRs), two for each channel, which allow you to calibrate each of the card’s four output channels. The following information outlines the function of each VR. Refer to the illustration shown below for the locations of the PCI1720’s VRs. Figure A-1: PCI-1720 VR assignment 30 VR1 Channel 0’s full scale (gain) adjustment. VR2 Channel 1’s full scale (gain) adjustment. VR3 Channel 2’s full scale (gain) adjustment.
You should use a precision voltmeter/ammeter to obtain accurate readings when calibrating the PCI-1720. Standard procedures for performing a calibration are given below. A.2 Unipolar Output Calibration 1. Select an appropriate output range for the channel to be calibrated. 2. Set all digital input codes to 0. Then adjust VRn (n = 5, 6, 7, 8 depending on what channel is to be calibrated, see prior page) until your voltmeter’s reading is 0.000 volts. 3.
A.4 Current Sink Calibration 1. Select the 0 ~ +5 V (unipolar) output range for the channel to be calibrated. 2. Set all digital input codes to 0. Then adjust VRn (n = 5, 6, 7, 8 depending on what channel is to be calibrated, see prior page) until your ammeter’s reading is 0.00 mA or 4.00 mA (Depending on jumper setting JP1 to JP4, see Section 3.1.1). 3. Set all digital input codes to 1.
