Overview
The Allen-Bradley 1756-OB16IS is a discrete DC output module designed for the ControlLogix platform. It provides 16 individually isolated sinking/sourcing outputs with 8 of the outputs being schedulable. The “IS” designation indicates individually isolated outputs, which provide electrical isolation between channels—a critical feature for applications where each output must operate independently without cross-talk or ground reference issues.
Key Features
- 16 Individually Isolated Outputs: Each output channel can be independently configured for sinking or sourcing operation, allowing flexible wiring arrangements and multi-voltage systems.
- 8 Scheduled Outputs: Dedicated scheduled output points for time-critical control operations within the ControlLogix environment.
- Electronic Fusing: Built-in electronic protection prevents excessive current flow and enhances module reliability without requiring external fuses.
- Point-Level Diagnostics: Status LEDs and fault detection enable rapid troubleshooting of open-wire and overload conditions.
- Compact Chassis Mount: Single-slot design integrates directly into any available 1756 ControlLogix chassis slot.
Technical Specifications
- Number of Outputs: 16 (individually isolated), 8 scheduled
- Output Voltage Range: 10–30 V DC nominal
- Current Rating: 1 A per point at 10–30 V DC
- Maximum Module Current: 8 A at 30°C; 4 A at 60°C
- Voltage Drop (ON State): 1.2 V DC maximum at 2 A
- Switching Delay: 1 ms OFF-to-ON; 2 ms ON-to-OFF
- Leakage Current: 0.5 mA per point
- Backplane Current Draw: 350 mA at 5.1 V DC; 2.5 mA at 24 V DC
- Backplane Power Consumption: 1.8 W maximum
- Power Dissipation: 3.6 W at 60°C
- Operating Temperature: 0–60°C
- Mounting: 1756 ControlLogix chassis (single slot)
- Control Contact Rating: 2 A (DC-13SQ)
Typical Applications
The 1756-OB16IS excels in industrial automation environments requiring independent, isolated digital outputs:
- Robotic Systems: Control robot arm movements, grippers, and auxiliary devices on assembly lines.
- Conveyor & Material Handling: Manage belt speeds, diverters, and sortation equipment with fast switching response.
- Pump & Valve Control: Operate multiple independent solenoid valves or pump motors in process control applications.
- Pharmaceutical & Food Processing: Coordinate automated mixing, filling, and packaging machinery with precise timing and safety isolation.
- Water Treatment & Utilities: Control alarms, dosing valves, and level-control equipment with reliable fault detection.
Compatibility & Replacements
Compatible With
- ControlLogix 1756 chassis (any available slot)
- ControlLogix processors (1756-L5, 1756-L6, 1756-L7x, 1756-L8x series)
- EtherNet/IP networks via ControlLogix chassis
- ControlNet and industrial Ethernet communication interfaces
- Studio 5000 Logix Designer software (all current versions)
- Allen-Bradley Removable Terminal Blocks (RTB) and 1492 Interface Modules (IFM)
Replaces / Drop-In Replacement For
The 1756-OB16IS directly replaces the earlier 1756-OB16 standard (non-isolated) output module in applications requiring individual channel isolation. Verify application compatibility with your system integrator before substitution, as output isolation characteristics differ.
Works With
- Studio 5000 Logix Designer: Native I/O configuration and diagnostics within RSLogix 5000 environment.
- FactoryTalk Suite: Monitoring and alarming via FactoryTalk View and FactoryTalk Optix.
- EtherNet/IP Protocol: Remote chassis operation across industrial Ethernet networks.
- 1756 Removable Terminal Blocks (RTB): 36-pin RTB housing required for field-side wiring termination (sold separately).
- 1492 Interface Modules (IFM): Alternative wiring termination interface for modern installations.
