Description
Description
The Allen-Bradley 1756-CNB is a ControlLogix ControlNet Communication Bridge module designed to facilitate high-speed data exchange between a ControlLogix controller and a ControlNet network. As a critical component in the ControlLogix architecture, this module manages the transfer of I/O data and messaging across the network, supporting up to 99 nodes and 64 connections. It provides a reliable interface for distributed control systems requiring deterministic communication performance.
Features
- Supports ControlNet communication at a rate of 5 Mbps.
- Provides a single ControlNet port for network connectivity.
- Designed for seamless integration into the ControlLogix chassis.
- Supports up to 99 nodes and 64 connections for scalable network configurations.
- Efficient power management with low thermal dissipation.
Technical Specifications
| Product Model |
1756-CNB |
| Module Type |
ControlNet Bridge Module |
| Communication Rate |
5 Mbps |
| Maximum Nodes |
99 |
| Maximum Connections |
64 |
| Input Current |
970 mA at 5.1 VDC; 1.7 mA at 24 VDC |
| Power Dissipation |
5.1 Watts |
| Thermal Dissipation |
17.4 BTU/hr |
Installation Guidelines
- Ensure the ControlLogix chassis is powered down before inserting or removing the module.
- Slide the module into the designated slot in the chassis and ensure it is fully seated before tightening the mounting screws.
- Use appropriate ControlNet cabling and ensure proper termination at both ends of the network segment to maintain signal integrity.
- Maintain adequate clearance around the chassis to ensure proper airflow and cooling.
- Avoid routing communication cables near high-voltage lines or sources of electromagnetic interference (EMI).
- Follow standard ESD (Electrostatic Discharge) precautions when handling the module.
FAQ
What is the primary function of the 1756-CNB?
The 1756-CNB acts as a bridge between the ControlLogix backplane and the ControlNet network, allowing the controller to communicate with remote I/O and other controllers on the network.
Does this module require external power?
No, the 1756-CNB draws its required power directly from the ControlLogix chassis backplane.
What is the maximum data rate for this module?
The 1756-CNB supports a fixed ControlNet communication rate of 5 Mbps.
