Allen-Bradley 1746-IA8 SLC 500 Digital Input Module

Allen-Bradley 1746-IA8 is an eight-channel digital input module for the SLC 500 family that accepts 100–120 VAC field signals and plugs into a 1746 backplane. Designed as an open-style I/O module, it provides eight discrete input points that read AC on/off states from field devices when connected to a 1746 chassis. Key electrical characteristics include a nominal input voltage of 100–120 VAC at 50/60 Hz; per-channel input current of about 12 mA at 120 VAC; an off-state current of up to 2 mA and an off-state voltage of up to 30 VAC; signal delays of approximately 35 ms on and 45 ms off; and an inrush current spec of up to 0.8 A for up to 0.5 ms. Backplane current consumption is about 0.050 A at the 5 V rail for the IA8, aligning with other IA-series modules, and the unit is designed to mount in an SLC 500 rack alongside other I/O modules to share a common backplane. Typical applications include expanding discrete input capability for sensors, switches, and other binary field devices in legacy SLC 500 automation setups that require 115 VAC input signaling.