描述
尽管用PLC实现对系统的控制可不用外部设备，配置好合适的模块就行了。然而，要对PLC编程，要监控PLC及其所控制的系统的工作状况，以及存储用户程序、打印数据等，就得使用PLC的外部设备。故一种PLC的性能如何，与这种PLC所具外部设备丰富与否，外部设备好用与否直接相关。
National Instruments 186936A-01, 16 port break out box
NATIONAL INSTRUMENT SCXI-1327 HIGH VOLTAGE BLOCK MODULE
National Instruments MXIbus Cable
National Instruments GPIB-VXI C SIZE MODULE
One-day shipping available
National Instruments CB-68LPR 68-Pin IO Connector Block
National Instruments SH100100 2-Meter E-Series Cable
National Instruments GPIB-485CT-A; GPIB = RS-485/422
NATIONAL INSTRUMENTS PCI-6503 24 chan Digital I/O
NATIONAL INSTRUMENTS PCI-232/485 2CH 84686A-01
National instruments MXI-4 controller copper cable NI
National Instruments- 2M GPIB Cable- 763061-02
National Instruments NB-GPIB Mac NuBus Card 180510-01
