Positive or Negative Inputs

Inputs for this module can be either positive or negative (all 16 inputs must be the same type).

Both types of signal produce a logic 1 (true) when the switch is closed. Selection of positive or

negative operation is made by the manner in which the external power supply is connected to

the inputs and to the I/O Terminal Block.

Positive inputs receive current from input devices and supply current to the common or

negative power bus. Input devices are connected between the positive power bus and the input

terminals.

Negative inputs provide current to input devices and accept current from the common or

positive power bus. Input devices are connected between the negative power bus and the input

terminal.

 Field Wiring

The following illustration shows terminal assignments for the 48 VDC Positive/Negative

Input Module.