Overview
The Allen-Bradley 1746-OB32 is a high-density digital DC output module engineered for the SLC500 programmable logic controller platform. This Series D module delivers 32 points of transistor-source output in a compact form factor, making it ideal for controlling solenoids, contactors, pilot lamps, and other low-current DC-operated industrial devices. The module operates across a wide voltage range and integrates directly into any available SLC500 chassis slot (except slot 0) for local or remote I/O applications.
Key Features
- 32-point transistor-source digital output module with two groups of 16 outputs per common
- Wide operating voltage range of 5–50 VDC with nominal 24 VDC output
- High-density, low-current design for cost-effective automation solutions
- Fast response time: 0.1 ms ON delay, 1.0 ms OFF delay
- Output isolation tested at 1500 VAC for 1 minute, ensuring circuit protection
- Low backplane current draw at 190 mA @ 5 VDC for reduced power infrastructure demands
Technical Specifications
The Allen-Bradley 1746-OB32 features reliable specifications verified for industrial automation environments. Each output point delivers 0.25 A at 0–60°C normal operating conditions, with surge current capability of 1.0 A for 10 ms (repeatable every 1 second at 30°C). Maximum circuit current leakage in the OFF state remains below 1 mA, ensuring clean switching and minimal phantom loading. The module occupies one slot in the host SLC500 chassis and may be deployed as fixed or modular hardware.
Typical Applications
- Discrete solenoid and valve control in process automation
- Motor starter and contactor actuation
- Pilot lamp, beacon, and alarm indicator control
- Low-current relay and signal device activation
- Factory automation and material handling systems
- OEM machinery and control panel integration
Compatibility & Replacements
Compatible With
- SLC500 fixed and modular chassis (all slots except 0)
- SLC500 programmable logic controllers
- Local and remote I/O networks
- RSLogix 500 software environment
- Standard SLC500 backplane communication
Replaces / Drop-In Replacement For
- 1746-OB32 Series A through Series C (same pinout and functionality)
- 1746-OB32E (earlier isolated variant)
- Direct replacement for identical part numbers across series revisions
Works With
- RSLogix 500 programming software
- Allen-Bradley SLC500 processor architecture
- Standard 24 VDC control logic systems
- Industrial Ethernet and serial remote I/O protocols supported by SLC500 gateway modules










