描述
继电器控制逻辑使用了大量的机械触点，连线也多，可靠性和可维护性差。而PLC采用微电子技术，大量的开关动作由无触点的半导体电路来完成，PLC还配有自检和监督功能，可靠性和可维护性好。
HP/Agilent 37776A-014 Optical Interface 155/622 Mb/s –
HP/Agilent 66106A DC Power Module, 200V 0.75A
HP/Agilent 3324A-002 1 to 21 MHz Synthesized Function /
HP/Agilent 4934A Transmission Impairment Measuring Set
HP/Agilent 54721A Oscilloscope Amplifier
HP/Agilent 33322H-std Programmable Variable Attenuator,
HP/Agilent 6627A Quad Output DC Power Supply
HP/Agilent E4201A 2.048 Mb/s E1 Cell Line Interface VXI
HP/Agilent E3642A Programmable Power Supply, 20V, 5A
HP/Agilent Z2468A VXI Module, 32 Channel 5 Amp, MOSFet
HP/Agilent E2668A Single-Ended Connectivity Kit
HP/Agilent E1499A VXI, C-Size V382 Controller
