描述
I/O单元实际上是PLC与被控对象间传递输入输出信号的接口部件。I/O单元有良好的电隔离和滤波作用。接到PLC输入接口的输入器件是各种开关、按钮、传感器等。PLC的各输出控制器件往往是电磁阀、接触器、继电器，而继电器有交流和直流型，高电压型和低电压型，电压型和电流型。
Tektronix DAS9200 Digital Analysis System
Tektronix 1740A Waveform/Vector Monitor
Tektronix 11401-1C 500-MHz Programmable Digitizing Osci
Tektronix 1910 NTSC Generator
Tektronix 1503C TDR
Tektronix 1730HD NTSC Waveform Monitor
Tektronix TDS520 Two Channel Digitizing Oscilloscope, 5
Tektronix ST104A Sonet Transmission Test Set
Tektronix SD46 Optical-Electrical Converter, DC-20 GHz,
Tektronix ST104A-OC3 Sonet Transmission Test Set. w/opt
Tektronix TLA714-1S Logic Analyzer Mainframe w/option 1
Tektronix TLA714 Logic Analyzer Mainframe w/option STD
