the role of input and output modules plc

plc input module for receiving, various parameters of the production process. put module(Start and stop input)
plc output module is used to send PLC operation after information received and completed by various control industrial field outside the machine actuators. (The result of using the output) If the digital module is the input and output signals of some switch, if it is analog module, that is an analog output signal of the.
1. A good anti-jamming capability.
2. to meet the matching requirements of various types of industrial field signals.