The PLC IO module describes

Interface PLC and the electrical circuit is output through the input section (IO) completed. plc IO module integrates the PLC IO circuit, the input registers reflect the state of the input signal, output point to reflect the state of the output latch. The input module signals into the electrical signals into digital PLC system, the opposite output module. IO into digital input (DI), switching output (DO), the analog input (AI), analog output module. Modular PLC including the cpu module, I / O modules, memory, power supply modules, backplane or rack, these modules can be configured according to certain rules of combination.