描述
从PLC控制系统与电器控制系统比较可知，PLC的用户程序（软件）代替了继电器控制电路（硬件）。因此，对于使用者来说，可以将PLC等效成是许许多多各种各样的“软继电器”和“软接线”的集合，而用户程序就是用“软接线”将“软继电器”及其“触点”按一定要求连接起来的“控制电路”。
National Instruments NI SCXI-1162HV 32 Channel Module
National Instruments Daq Card 700 Data Aquisition
Expedited shipping available
NATIONAL INSTRUMENTS GPIB-120A BUS EXPANDER / ISOLATOR
NATIONAL INSTRUMENTS SCXI-1160 16 CHANNEL SPDT RELAY
National Instruments MKI-2/M2 777164-02 Cable; 2 Meter
National Instruments FP-DI-330 Universal Input
National Instruments FP-DI-330 8-Channel Input Module
National Instruments GPIB-VXI/C VXI Module 181520G-0110
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NATIONAL INSTRUMENTS MICRO GPIB CABLE
NATIONAL INSTRUMENTS NI PCMCIA-GPIB #186736C-01 Tested
NEW NATIONAL INSTRUMENTS MEMORY 128 MB SDRAM 777885-128
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National Instruments NB-DMA-8 Direct Memory Access GPIB
