The Allen-Bradley 1756-CN2 is a ControlNet communication interface module used in the ControlLogix PLC system from Rockwell Automation. It enables high-speed, deterministic communication between ControlLogix controllers and other ControlNet-compatible devices within industrial automation networks.
The module supports scheduled and unscheduled data transfers over the ControlNet network, making it suitable for real-time control applications where precise timing and reliability are required.
It is widely used in process industries such as manufacturing, oil & gas, power generation, and material handling systems.
Technical Specifications
| Parameter | Details |
|---|---|
| Product Type | ControlNet Communication Module |
| Model | 1756-CN2 |
| System Compatibility | Allen-Bradley ControlLogix |
| Network Type | ControlNet |
| Communication Rate | 5 Mbps |
| Channels | 1 or 2 ControlNet ports (depending on revision) |
| Data Transfer | Scheduled & unscheduled messaging |
| Redundancy Support | Yes (dual network capable) |
| Power Consumption | ~3–5 W |
| Backplane Connection | ControlLogix chassis backplane |
| Installation Type | Slot-mounted module |
| Operating Temperature | 0°C to 60°C |
The 1756-CN2 provides deterministic, time-critical communication for distributed ControlLogix systems using ControlNet architecture.
Physical Dimensions & Weight
- Dimensions (H × W × D): 145 mm × 32 mm × 135 mm
- Weight: ~0.3–0.5 kg
Compact design allows installation in standard ControlLogix chassis slots.
Function in ControlLogix System
The 1756-CN2 is used to:
- Connect ControlLogix controllers to ControlNet networks
- Enable real-time deterministic communication
- Support scheduled I/O data exchange
- Support peer-to-peer controller communication
- Provide network redundancy (in dual-channel configurations)
Recommended Related Models
- Allen-Bradley 1756-CN2R (Redundant ControlNet module)
- Allen-Bradley 1756-EN2T Ethernet module
- Allen-Bradley 1756-IB16 Digital Input module
- Allen-Bradley 1756-OB16E Digital Output module
- Allen-Bradley 1756-L7x ControlLogix controllers
