Allen-Bradley 1771-OGC 8-Channel TTL Output Module

Allen-Bradley 1771-OGC TTL Output Module is an eight-channel digital output module for PLC-5 systems that plugs into the 1771 I/O backplane. It provides eight TTL-level outputs designed to drive 5V logic devices and TTL-compatible loads in industrial automation. The module is intended for installation in any 1771 I/O chassis slot and is powered through the 1771 backplane from the chassis power supply, facilitating straightforward integration without requiring a separate 5V supply in typical configurations. Each channel delivers a TTL output suitable for signaling transistors, relays, or indicator circuits used in PLC-5 control networks, and the unit supports both sourcing and sinking configurations for flexible wiring and load management. Common applications include expanding digital control for remote I/O, status indication, and logic-level control of actuators within PLC-5 installations. The 1771-OGC is part of Allen-Bradley’s 1771-series I/O and remains compatible with universal 1771 backplanes such as 1771-A1B, 1771-A2B, 1771-A3B, and 1771-A4B, making it a straightforward TTL-output option for PLC-5 systems that rely on TTL-level signals.