Wiring Diagrams of PLC and DCS Systems - DI, DO, AI, AO
ON state mean PLC DI point received status in form of electrical power (can be 24 VDC, 120 VAC, etc.) and OFF state mean PLC DI point received no power from devices. An example of a Digital input device is a switch. DO or discrete/digital output is the type of PLC output which used to control digital output devices. Digital output devices only ...