Overview
The Allen-Bradley 1746-OB16 Series D is a digital DC output module designed for the SLC 500 programmable controller platform. Manufactured by Allen-Bradley/Rockwell Automation, the 1746-OB16 Series D module is a digital DC output module in the SLC 500 series. This DC module comes with sixteen 24 Volts DC outputs and can be mounted on any of the 1746 I/O chassis’s free slots. This module delivers reliable output switching for discrete device control in machine automation, material handling, HVAC systems, and process control applications.
Key Features
- 16 Output Points: Features 16 output points along with a backplane electrical rating of 0.28 Amps at 5 Volts DC or 0 Amps at 24 Volts DC.
- Electronic Overload Protection: The 1746-OB16 module is a DC output module which features electronic protection against current overload and short circuit conditions. This protection is based on a thermal cut-out principle: when an overload or short circuit occurs on any particular output channel, the module will limit the current on that channel within milliseconds once the temperature threshold has been reached.
- Fast Signal Switching: The module features a load-dependent total signal delay time of 0.1 milliseconds for the on state and 1 millisecond for the off state.
- Compact Single-Slot Design: The module is a single slot module that fits to any slot of an SLC 500 chassis except the leftmost module which is reserved for the processor or communication module.
Technical Specifications
The following specifications define the 1746-OB16 Series D’s electrical and operational parameters:
- Output Voltage Range: 10V to a maximum of 50V DC
- Nominal Output Voltage: 24V DC
- Output Current per Channel @ 30°C: 0.5 Amp
- Output Current per Channel @ 60°C: 0.25 Amp
- Total Module Current @ 30°C: 8.0A
- Total Module Current @ 60°C: 4.0A
- Backplane Current (5V DC): 0.28 Amps
- Heat Dissipation per Output: 0.388 watts
- Total Heat Dissipation: 7.6 watts
- ON-State Voltage Drop: 1.2 Volts at 0.50 Amps
- OFF-State Leakage Current: 1 milliamp maximum
- Minimum Load per Output: 1 milliamp
- Weight: Approximately 240–250 grams
Typical Applications
The 1746-OB16 is commonly deployed in:
- Material handling and conveyor control systems
- HVAC and process automation
- Assembly line machine control and interlocking
- Pump and motor starter circuits
- Solenoid and valve activation
- Indicator lamp and alarm signaling
- Simple motion control and position control
Compatibility & Replacements
Compatible With
- SLC 500 fixed and modular processors
- 1746 series I/O chassis (all slots except leftmost processor slot)
- RSLogix 500 programming software
- Standard 24V DC control circuits and devices
Replaces / Drop-In Replacement For
- Earlier revisions of the 1746-OB16 (compatible Series A, B, C)
- Verify specific model compatibility with your system integrator before ordering
Works With
- RSLogix 500 (legacy SLC 500 programming environment)
- Allen-Bradley Studio 5000 (via SLC 500 compatibility mode)
- Standard industrial 24V DC signals and loads
- PLC automation networks and distributed I/O systems
