The Allen-Bradley 1756-DHRIO is a ControlLogix communication interface module designed to provide connectivity between ControlLogix controllers and Data Highway Plus (DH+) networks or Remote I/O (RIO) networks. This module functions as a bridge, allowing for seamless data exchange and device management across legacy and modern industrial communication architectures.
Features
Dual-channel communication interface for versatile network integration.
Supports Data Highway Plus (DH+) communication protocol.
Functions as a Remote I/O (RIO) scanner for distributed control applications.
Selectable communication speeds: 57.6 Kbaud, 115.2 Kbaud, and 230.4 Kbaud.
Designed for seamless integration into the ControlLogix chassis backplane.
Applications
The 1756-DHRIO is typically utilized in industrial automation environments requiring the integration of legacy DH+ networks or RIO-based field devices into a modern ControlLogix platform. It is commonly found in manufacturing, process control, and material handling systems where legacy infrastructure must be maintained alongside newer control hardware.
Technical Specifications
Module Type
Communication Interface Module
Communication Channels
2
Communication Speeds
57.6 Kbaud, 115.2 Kbaud, 230.4 Kbaud
Current Draw
850 mA @ 24 VDC
Recommended Cable
Belden 89463 twinaxial (0.52 mm2 / 20 AWG)
Max Cable Length
Up to 3048 m (10,000 ft) depending on baud rate
Installation Guidelines
Ensure the ControlLogix chassis power is disconnected before installing or removing the module.
Slide the module into the designated chassis slot and secure it using the top and bottom latching mechanisms.
Use shielded twinaxial cable (e.g., Belden 89463) for all DH+ and RIO connections to minimize EMI interference.
Maintain proper grounding practices for the communication shield to prevent noise-related communication errors.
Verify that the baud rate settings on the module match the existing network configuration before commissioning.
FAQ
What is the primary function of the 1756-DHRIO module?
The module acts as a communication bridge, enabling a ControlLogix controller to communicate with devices on a Data Highway Plus network or to act as a scanner for Remote I/O networks.
Can this module be used for both DH+ and RIO networks?
Yes, the 1756-DHRIO is designed to support both DH+ and Remote I/O communication protocols, providing flexibility for legacy system integration.
