Abstract: A digital input/output circuit board includes a plurality of module receptacles for selectively mounting input modules or output modules, wiring terminals for attaching field wires to electrically connect the circuit board to field devices, a hot wiring terminal for attaching a hot power wire, a neutral wiring terminal for attaching a neutral power wire, and a device for selecting the status of each of the module receptacles as either an input or an output, to enable a computer connected to the circuit board to receive input signals to read the state of the field devices and to send output signals to activate other field devices.

Abstract: A digital input/output circuit board includes a plurality of circuits each having an input module and an output module for mounting either an input module or an output module, wiring terminals for attaching field wires to electrically connect the circuit board to field devices, a hot wiring terminal for attaching a hot power wire, and a neutral wiring terminal for attaching a neutral power wire. A computer connected to the circuit board receives input signals indicating the state of the field devices and sends output signals to activate other field devices.