Description

Brief Product Description

The Allen Bradley 1756-DHRIO is a high-performance ControlLogix communication interface that facilitates seamless data exchange between modern processors and legacy networks. It features two independent channels supporting Data Highway Plus (DH+) and Remote I/O (RIO) protocols to ensure system interoperability during phased automation upgrades.

Product Description

Legacy Network Integration

The Allen Bradley 1756-DHRIO serves as a vital bridge for industrial facilities transitioning from older PLC platforms to the ControlLogix architecture. By providing two independent, configurable channels, this module allows a ControlLogix chassis to communicate directly with legacy PLC-5 and SLC 500 systems. The hardware supports both DH+ messaging for inter-processor communication and Remote I/O scanning for controlling distributed field devices. This dual-protocol capability eliminates the need for immediate hardware overhauls, allowing engineers to maintain existing network infrastructure while upgrading primary control logic.

Versatile Signal Optimization

To accommodate different cable lengths and network complexities, the 1756-DHRIO module offers selectable communication rates including 57.6, 115.2, and 230.4 Kbaud. When utilizing high-quality shielded twinaxial cable, such as Belden 89463, the module can drive signals across distances reaching up to 3,048 meters. This extended range ensures that remote expansion racks remain synchronized with the central controller even in sprawling plant environments. Furthermore, the 3-pin terminal block design simplifies the physical wiring process, providing a secure and vibration-resistant connection point for critical data paths.

Thermal Management and Chassis Efficiency

Engineered for continuous operation within dense control cabinets, the AB 1756-DHRIO prioritizes thermal stability and power efficiency. The module draws a maximum of 850 mA from the 24V DC backplane and only 1.7 mA from the 5V rail, resulting in a low power dissipation of approximately 4.5 watts. This efficient power profile minimizes heat buildup within the 1756 chassis, extending the lifespan of adjacent components. Additionally, the module’s open-style enclosure promotes natural airflow, ensuring that internal electronics stay within the 0 to 60°C operating window required for demanding industrial automation sectors.

Technical Specifications