The 1756-OB8I ControlLogix Digital DC Output Module from Rockwell Automation is a compact 8-point individually isolated 24V DC output module designed for industrial automation systems that require high electrical isolation, stable switching performance, and flexible wiring architecture in a small I/O footprint.
Unlike standard 8-point output modules, the 1756-OB8I provides point-to-point isolation, helping reduce ground-loop issues, improve fault containment, and increase system reliability in electrically noisy environments. It is widely used in OEM machinery, process control systems, packaging equipment, and distributed automation architectures where reliability and wiring flexibility are critical.
Technical Specifications (Including Size & Weight)
| Parameter | Specification |
|---|---|
| Model | 1756-OB8I |
| Series | ControlLogix Isolated Output Modules |
| Module Type | 8-Point Isolated DC Output Module |
| Number of Outputs | 8 individually isolated outputs |
| Output Voltage Range | 10–30V DC |
| Nominal Voltage | 24V DC |
| Output Type | Sourcing/sinking transistor outputs |
| Isolation | 250V continuous (output-to-backplane and channel separation) |
| Continuous Current per Point | 1.0 A per channel |
| Output Configuration | Individually isolated channels |
| Switching Time | ~1 ms ON / ~2 ms OFF (typical) |
| Backplane Current (5.1V DC) | ~150–200 mA |
| Power Dissipation | ~2.5–3.5 W |
| Field Power Requirement | External 24V DC supply required |
| Terminal Block | 1756-TBSH / 1756-TBCH |
| Operating Temperature | 0°C to 60°C |
| Storage Temperature | -40°C to 85°C |
| Humidity | 5%–95% non-condensing |
| Weight | ~0.30–0.40 kg |
Physical Dimensions
- Size (H × W × D): 145 × 35 × 140 mm
This standard ControlLogix single-slot footprint ensures easy integration into existing chassis layouts while supporting isolated point-level wiring flexibility.
Recommended Related Models
The 1756-OB8I is commonly used with:
- 1756-IB8 / 1756-IB16 digital input modules
- 1756-OB8 standard DC output module
- 1756-OB16 higher-density DC output module
- 1756-OA8 / 1756-OA16 AC output modules
- 1756-OW16 relay output module
- 1756-L71 / L73 ControlLogix processors
Popular Allen-Bradley ControlLogix Output Modules
Within the ControlLogix output family, commonly used models include:
- 1756-OB8I isolated DC output module
- 1756-OB8 standard DC output module
- 1756-OB16 high-density DC output module
- 1756-OB16E electronically fused output module
- 1756-OA16 AC output module
These modules are selected based on isolation needs, channel density, and system complexity.
