1756-DHRIO Allen-Bradley | ControlLogix Communication Module

Allen-Bradley ControlLogix DH+/Remote I/O Bridge Module 1756-DHRIO

The Allen-Bradley 1756-DHRIO is a versatile communication interface for ControlLogix systems. It bridges modern controllers with legacy Data Highway Plus (DH+) and Remote I/O networks. This dual-channel module enables seamless data exchange across mixed device environments.

Core Specifications

• Brand & Model: Allen-Bradley 1756-DHRIO
• Series: ControlLogix Communication Module
• Function: DH+/Remote I/O Bridge and Scanner
• Channels: 2 Independent Ports (Channel A & B)
• Supported Protocols: Data Highway Plus (DH+), Remote I/O (RIO)
• Communication Speed: 57.6, 115.2, or 230.4 Kbaud (selectable)
• Backplane Current: 1.7A @ 5V DC, 850 mA @ 24V DC
• Power Dissipation: 4.5 Watts Max (15.4 BTU/hour)

Key Features

• Dual Protocol Support: Acts as a bridge for both DH+ peer-to-peer messaging and Remote I/O scanning.
• Legacy Integration: Connects ControlLogix to PLC-5, SLC, Flex I/O, and Point I/O systems.
• Flexible Topology: Supports daisy-chain networks with proper termination.
• Hot Swap Capable: Can be installed/removed from a powered chassis (in non-hazardous areas).
• High Connection Capacity: Supports up to 32 Logix connections for efficient data handling.

Installation & Wiring

• Recommended Cable: Belden 89463 Twinaxial (20 AWG).
• Cable Length vs Speed: Up to 10,000 ft at 57.6 Kbaud; shorter lengths for higher speeds.
• Termination: Requires 82Ω or 150Ω resistor at each network end, based on baud rate.
• Connector Kit: Phoenix MVSTBR2.5/3-ST BK AU terminal blocks.
• Wiring: Uses 3-pin terminals per channel (Line 1, Shield, Line 2) plus an 8-pin mini-DIN port.
• ESD Warning: Handle with static precautions; module is sensitive to electrostatic discharge.

Physical & Environmental

• Operating Temperature: 32° to 140°F (0° to 60°C)
• Weight: 0.64 lbs (0.293 kg)
• Slot Width: 1 Slot in 1756 ControlLogix Chassis
• Enclosure: Open Type (for installation inside a chassis)
• Network Limits: Can bridge messages through up to 3 chassis and 4 networks.

Packaging & Shipping

• One Allen-Bradley 1756-DHRIO communication module.
• Secure packaging to prevent damage.
• Shipped via FedEx, UPS, or DHL.

FAQ

• What is the main purpose of this module?
  It allows modern ControlLogix controllers to communicate with older DH+ networks and Remote I/O devices, facilitating system upgrades and integration.
• Can both channels operate differently?
  Yes, each channel can be independently configured as either a DH+ or a Remote I/O network.
• Is special software needed for configuration?
  Yes, you configure the network type and parameters using Rockwell Automation's RSLogix 5000/Studio 5000 software.