1756-DHRIO  Product datasheet     

1756-DHRIO  Functional Description    

The 1756-DHRIO Communication Module AB is a crucial communication interface module within the ControlLogix system platform, designed to bridge modern control architectures with legacy networks. This versatile module features two independent communication channels, each equipped with 3-pin terminal blocks for flexible wiring of either Data Highway Plus (DH+) or Remote I/O networks. It supports multiple communication speeds including 57.6 Kbaud, 115.2 Kbaud, and 230.4 Kbaud, allowing optimization for various network requirements and cable lengths. Its robust design ensures reliable operation in industrial environments with an operating temperature range of 0-60°C (32-140°F).

The physical implementation of the Scanner Module ALLEN BRADLY 1756-DHRIO requires installation in a 1756 ControlLogix chassis, where it efficiently manages backplane power consumption at just 1.7 milliamps on the 5V rail and 850 milliamps on the 24V rail. With a maximum power dissipation of 4.5 watts and thermal dissipation of 15.4 BTU per hour, it maintains stable operation without excessive heat generation. The module's open enclosure design facilitates natural cooling while its compact form factor weighing only 0.63 lbs (0.28 kg) allows flexible mounting within the chassis. These technical characteristics make it suitable for high-density control panel configurations.

Network connectivity through the 1756-DHRIO ROCKWELL high-performance ControlLogix communication module supports substantial cable distances, achieving up to 3048 meters (10,000 feet) at lower baud rates with recommended Belden 89463 twinaxial cable. This 20 AWG cable rated for 200°C (392°F) ensures reliable data transmission even in electrically noisy industrial environments. It ability to handle both DH+ messaging and Remote I/O scanning simultaneously provides significant advantages for system integrators managing hybrid automation networks. This dual-protocol support enables seamless data exchange between ControlLogix processors and legacy PLC systems.

Practical applications of the CONTROL LOGIX COMMUNICATION MODULE 1756-DHRIO Allen-Bradly extend across various industrial sectors where migration from older control systems must be implemented gradually while maintaining existing network infrastructure. The module's proven reliability and flexible configuration options make it an ideal solution for maintaining communication with PLC-5, SLC 500, and other legacy devices while transitioning to modern ControlLogix architecture. This backward compatibility, combined with robust construction and efficient power management, ensures it remains a valuable component in industrial automation systems requiring long-term stability and network integration capabilities.