Allen-Bradley 1756-IB16S ControlLogix Safety Input Module

Allen-Bradley 1756-IB16S ControlLogix Safety Input Module is a 16-channel, sinking safety input card for ControlLogix Safety I/O, designed to monitor 24 VDC safety devices such as E-stops and two-hand controls. It accepts field safety signals in a 10–30 VDC range and connects via a 36-pin interface to a removable terminal block (1756-TBCHS) for field wiring. The module draws about 280 mA at 5.1 V for its internal logic and dissipates up to 6 W, with a total backplane power budget of 150 VA. Isolation is 60 V continuous between channels and the backplane, with no isolation between channels or between field power and channels. The 16 inputs are monitored independently and can be configured for dual-channel safety architectures, enabling SIL CL3 / PLe / Cat 4 safety sub-system operation when used with appropriate safety devices and SRP/CS configurations. The module provides safety test outputs (18–32 V DC, up to 200 mA) for periodic channel verification, and uses standard 1756 I/O backplane connections with a removable terminal block housing (RTB) 1756-TBCHS, and compatible wire sizes 22–14 AWG (0.33–2.1 mm2) for field wiring. Commonly paired with safety-enabled Rockwell controllers in ControlLogix racks, the 1756-IB16S is used to interface 16 safety input signals to the controller for monitoring safety devices and ensuring compliant safe operation.