How to quickly test a Power-io IO-IDC Module, using two 9 volt batteries and a meter.

IO-IDC-028-N or -P generates a logic signal on terminal 4 that is often wired to a PLC's input. The PLC's power supply is wired to terminals 3 and 5.

The "-N" model produces a logic signal that is negative compared to the input. (If a field device input exists, no output exists). The "-P" model produces a logic signal that is positive compared to the input. (If a field device input exists, an output exists).

Terminal 4 becomes a sourcing input into a PLC. When terminal 4 is at 0 volts, it can be used as a sinking signal if that is how your PLC is being used.

When a control input signal is present on terminals 1 and 2, the logic signal on terminal 4 changes state, and a green LED activates.

If the LED is ever red in color, the + and - polarity is probably mis-wired.

When installed in your application, the Power-io IO modules might be used like this:

The modules can be intermixed as input IO modules and output IO modules: