The B814–108 relay output module converts signals from the PLC to eight independent relay outputs. Each output is capable of driving a relay, pilot lamp, motor starter, solenoid, or any other load up to 5.0 A. Each of the eight outputs is electrically isolated from the I/O bus and from the other seven outputs by the relay coil. The module is designed to withstand the high surge currents typical of industrial loads.

The module is user-configurable as to setting for normally-open or normally-closed operation of the relays as described below, and is compatible with other input modules. Assuming a normally-open configuration, when the relay coil is energized, the relay contacts will conduct current from output A terminal to output B terminal (see the following figure).