Overview
The Allen-Bradley 1746-OB16 is a solid-state DC output module from the SLC 500 series. This 16-point output device manages discrete digital signals at 24V DC and provides electronic protection against current overload and short circuit conditions. The Series D configuration delivers proven performance in legacy PLC systems and retrofit applications.
Key Features
- 16 independent output points with common returns
- 24V DC rated with operating voltage range from 10V to 50V DC
- Electronic thermal overload and short-circuit protection per channel
- Fast ON/OFF switching: 0.1 ms ON delay, 1.0 ms OFF delay (maximum resistive load)
- Low backplane current draw: 0.28A @ 5V DC, 0A @ 24V DC
- Maximum 1 mA off-state leakage current per channel
Technical Specifications
- Output Points: 16 DC outputs
- Output Voltage: 24V DC nominal (10–50V DC operating range)
- Max Current per Channel: 1.5A @ 30°C; 1.0A @ 60°C
- Max Module Current: 8.0A @ 30°C; 4.0A @ 60°C
- ON-State Voltage Drop: 1.2V maximum @ 0.50A
- OFF-State Leakage: 1 mA maximum
- Signal Delay (Max Resistive Load): ON: 0.1 ms; OFF: 1.0 ms
- Minimum Load Current: 1 mA per point
- Surge Current: 3.0A per point for 10 ms (repeats every 1s @ 30°C, every 2s @ 60°C)
- Backplane Current Consumption: 0.28A @ 5V DC; 0A @ 24V DC
- Operating Temperature: 0°C to 60°C
- Humidity: 5–95% non-condensing
- Shock Rating: 30G operating shock
- Vibration Rating: 2.5G @ 57–200 Hz
- Heat Dissipation: 7.6W total (0.388W per output point)
Typical Applications
- Discrete output control in legacy SLC 500 systems
- Solenoid, contactor, and pump motor control
- Indicator lamp and alarm signal drivers
- Thermal overload protection for solid-state switching loads
- Industrial process automation and machine control logic
- Facility retrofit and system modernization projects
Compatibility & Replacements
Compatible With
- Allen-Bradley SLC 500 PLC controllers and chassis
- SLC 500 I/O rack configurations
- RSLogix 500 programming software
- 24V DC power supplies (10–50V DC nominal range)
Replaces / Drop-In Replacement For
- 1746-OB16 Series A, B, C (same form factor and pinout)
- Verify compatibility with your original equipment documentation before substituting any earlier series
Works With
- RSLogix 500 configuration and diagnostics software
- Allen-Bradley programming terminals and PC-based development environments
- Standard 24V DC field equipment (solenoids, relays, indicators)
- Discrete digital control logic within SLC 500 ladder programs
