Allen-Bradley 1747-IB16 16-Point Input Module

The Allen-Bradley 1747-IB16 is a 16-channel 24 V DC input module for the SLC 500 PLC family. Designed to plug into a 1747 backplane within an SLC 500 chassis, it converts 24 V DC field signals into digital inputs that the controller can read for logic decisions. It uses current sinking (NPN) inputs, so an active device completes the circuit to a common ground, and it provides 16 discrete input channels that are commonly wired to sensors, limit switches, and other 24 V devices. The module is specified for fast response, with a module-wide scan time around 0.325 ms in typical configurations, enabling timely detection of state changes on production lines. As part of the 1747 I/O family, the IB16 supports modular expansion of a legacy automation install, allowing integration with other DC input modules and PLC logic to implement machine control, safety interlocks, and process monitoring. In practical terms, it’s a drop-in digital input solution for projects that require 24 V DC signals and reliable, field-wiring-friendly I/O in an industrial environment.