Allen-Bradley 1771-IQ16K-B Isolated DC Input Module

Allen-Bradley 1771-IQ16K-B is a 16-point isolated DC input module designed for PLC-5 1771 I/O chassis. This conformally coated variant (the “K”) provides galvanic isolation for each input channel, helping protect the controller from voltage transients and wiring faults in harsh industrial environments. The module is specified for 24V DC input signals and conveys 16 discrete digital inputs to the backplane, with a backplane current rating around 100 mA per module. It is compatible with 1771-series B or later I/O chassis, and its installation guidance notes that it must be used in a 1771 series B or later system to ensure proper signaling and isolation from field wiring. Typical applications include reading status from DC limit switches, proximity sensors, pushbuttons, and other 24V DC field devices in automation lines, machine control, and process control. The 1771-IQ16K-B addresses the need for isolated, noise-immune input collection in PLC-5 installations, delivering reliable digital input data to a PLC-5 processor by plugging into a 1771 I/O backplane and integrating with the appropriate 24V DC field power.