Allen-Bradley 1771-IGD 8-Point TTL Input Module provides eight 5V TTL digital input channels for PLC-5 systems, designed to mount in a 1771 I/O chassis and interface with the 1771 backplane. It accepts TTL-level input signals from sensors and switches and communicates their status to the PLC-5 program through the I/O rack. Power for the module is supplied via the 1771 I/O backplane, with no external power connection required. Common applications include reading digital signals from pushbuttons, limit switches, and other digital sensors in PLC-5 control schemes.
