Allen-Bradley 1746-IA8 Analog Input PLC Module

The Allen-Bradley 1746-IA8 is an eight-channel AC digital input module for the SLC 500 PLC family, designed to read 100–120 VAC field signals and present them as discrete inputs to the controller. It mounts in a 1746 backplane slot and interfaces with an SLC 500 processor to monitor eight independent input channels that are typically wired to common industrial devices such as pushbuttons, limit switches, or other 120 VAC sensors. Each channel provides individual input state to the PLC, enabling reliable polled or scanned input across an 8-point block. The module is rated for 100/120 VAC operation and draws about 0.050 A from the backplane. Catalog number 1746-IA8 is commonly used to expand the input capacity of an existing SLC 500 system, maintaining compatibility with standard 1746 series wiring and addressing conventions. In practice, it complements other discrete I/O options in the SLC-500 ecosystem, delivering straightforward integration for digital control tasks within industrial automation projects.