INPUT

INPUT represents the standard normally-open input device in the LADDER  symbology. This component may represent a physical input of PLC or a logical input to associate with a  RELAY device. To establish if an INPUT is physical or logical opportune value must be programmed on the REFERENCE parameter of the property dialog. If the REFERENCE value refers to a physical resource of the PLC then a physical INPUT will be created. If the REFERENCE field does not refer to any physical resources then the INPUT will be configured as logical input to associate with a RELAY device. This configuration is also called LOGICAL LINKS .

There's no limit on the INPUT devices that can be relationed with a RELAY device.

See also : EINPUT, NCINPUT, ENCINPUT, OUTPUT, EOUTPUT, RELAY