The 1756-OB8 ControlLogix Digital DC Output Module from Rockwell Automation is a compact 8-point 24V DC sourcing output module designed for reliable discrete control in industrial automation systems requiring stable switching, compact I/O design, and flexible integration within ControlLogix chassis platforms.
It is widely used in machine control panels, packaging equipment, conveyor systems, and general-purpose industrial automation where a small number of high-reliability DC outputs are needed. Despite its compact size, the module delivers strong industrial performance with fast switching response and robust electrical isolation.
This module is often selected for applications where simplicity, reliability, and space efficiency are more important than high-density output count.
Technical Specifications (Including Size & Weight)
| Parameter | Specification |
|---|---|
| Model | 1756-OB8 |
| Series | ControlLogix Digital Output Modules |
| Module Type | 8-Point DC Sourcing Output Module |
| Number of Outputs | 8 outputs |
| Output Voltage Range | 10–30V DC |
| Nominal Voltage | 24V DC |
| Output Type | Transistor (sourcing) |
| Output Configuration | 2 groups of 4 points |
| Continuous Current per Point | 2 A @ 60°C |
| Continuous Current per Module | 8 A total |
| Switching Time | ~1 ms ON / ~2 ms OFF |
| Off-State Leakage Current | ≤ 1 mA per point |
| Isolation Voltage | 250V continuous (backplane & group isolation) |
| Backplane Current (5.1V DC) | ~165 mA |
| Power Dissipation | ~2.5 W |
| Field Power Requirement | External 24V DC supply required |
| Terminal Block | 1756-TBNH / 1756-TBSH |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Humidity | 5%–95% non-condensing |
| Weight | ~0.40 kg |
Physical Dimensions
- Size (H × W × D): 145 × 35 × 140 mm
Even as an 8-point module, it maintains the standard ControlLogix single-slot form factor for seamless chassis compatibility and consistent system layout.
Recommended Related Models
The 1756-OB8 is commonly used with:
- 1756-IB8 / 1756-IB16 digital input modules
- 1756-OB16 higher-density DC output module
- 1756-OA8 / OA16 AC output modules
- 1756-OW16 relay output module
- 1756-L71 / L73 ControlLogix controllers
- 1756-EN2T EtherNet/IP communication modules
Popular Allen-Bradley ControlLogix Output Modules
Within the ControlLogix output family, widely used models include:
- 1756-OB8 compact DC output module
- 1756-OB16 standard DC output module
- 1756-OB16E electronically fused output module
- 1756-OB32 high-density DC output module
- 1756-OA16 AC output module
These modules are selected based on channel density, protection level, and application complexity.
