Product Overview

The Allen-Bradley 1746-OB16 is a 16-point current sourcing digital DC output module engineered by Rockwell Automation for the widely deployed SLC 500 modular PLC platform, serving as one of the most frequently specified discrete output cards across the entire Bulletin 1746 I/O catalogue. Categorised as a 24V DC sourcing module, the 1746-OB16 provides sixteen solid-state transistor outputs referenced to a single common, delivering the deterministic on/off actuation required for contactors, motor starters, solenoid valves, indicator stacks, relay coils, and low-voltage control circuits throughout general machine and process applications.

With an operating window of 10 to 50V DC, the Allen-Bradley 1746-OB16 tolerates realistic supply variation in field cabinets while remaining fully compatible with standard 24V DC control supplies. Each point is rated for 0.5 A continuous at 30°C (derating to 0.25 A at 60°C), with a module-level capacity of 8 A across the full ambient range and a surge tolerance of 2 A per point for 10 ms to absorb contactor coil inrush and indicator lamp cold-filament current without module damage. Signal switching delays are exceptionally short — 0.1 ms on and 1.0 ms off into resistive loads — providing the responsiveness needed for high-speed sequencing, interlock logic, and time-critical discrete control.

As a proven member of the SLC 500 ecosystem, the 1746-OB16 installs into any available 1746 chassis slot and is equipped with a colour-coded removable terminal block that accepts two 14 AWG conductors per point, allowing rapid module exchange without disturbing adjacent field wiring. Sixteen front-panel status LEDs give operators point-level visual feedback during commissioning and troubleshooting, and the module’s wiring can optionally be terminated through a Bulletin 1492 interface module with pre-wired cable for accelerated panel build and simplified field replacement. Because Rockwell Automation has transitioned the SLC 500 family to its mature lifecycle status, the 1746-OB16 is now predominantly supplied through specialist automation distributors as a lifecycle replacement part, with tested stock available to support the extensive installed base of SLC 500 systems still operating reliably across manufacturing, water treatment, automotive, and general process industries worldwide.

Technical Specifications