Allen-Bradley 1771-IBD 16-Point Digital Input Module

The Allen-Bradley 1771-IBD is a 16-point DC digital input module designed for the PLC-5 1771 I/O backplane. It accepts 16 DC input signals in the 10–30 V DC range and presents corresponding logic to the PLC-5 controller, making it ideal for monitoring field devices such as pushbuttons, proximity sensors, and limit switches in industrial automation. This module is a Series B DC input card intended for use with 1771 I/O chassis and is compatible with the PLC-5 I/O architecture, addressing through the backplane along with standard 1771 wiring hardware. The unit draws from the backplane with a typical current of about 130 mA and specifies a maximum off-state current of up to 2.0 mA per input, providing predictable leakage characteristics for reliable dry-contact or solid-state sensing. Field wiring is supported via standard wiring arms (1771-WH and 1771-WN) to connect sensors and harnesses to the 16 inputs. For responsiveness, the module exhibits a typical DC signal delay in the vicinity of 1.3 milliseconds when transitioning on, and a similar 1.3-millisecond characteristic when transitioning off, enabling synchronized input timing within PLC-5 control solutions. Overall, the 1771-IBD delivers a compact, 16-channel DC input interface tailored for PLC-5 PLCs, balancing straightforward installation with dependable 10–30 V DC sensing across all channels.