Allen-Bradley 1785-BEM Backup Communication Module

The Allen-Bradley 1785-BEM facilitates high-availability networking for PLC-5 controller systems. This expansion module enables reliable communication redundancy between primary and secondary processors. It specifically prevents data loss during unexpected hardware failures or network interruptions. Furthermore, the module ensures continuous data synchronization for critical industrial processes. It fits into a single slot within a standard 1771 I/O chassis for easy integration.

High-Speed Data Transfer and Connectivity

This expansion module supports rapid information exchange to maintain system synchronization. It utilizes specialized connectors to interface with standard Data Highway Plus (DH+) and Remote I/O networks.

• Maximum Communication Speed: 1.2 Mega Baud
• Backplane Current Load: 0.6 Amps at 5V DC
• Input Capability: 32-bit processor image table support
• Network Compatibility: DH+ and Remote I/O (RIO)
• Cable Interface: 1771-CD connector
• Integrated Relay: 0.25 Amps at 24V DC factory-installed relay

Configuration and Installation Features

The 1785-BEM includes user-adjustable components for precise site configuration. A four-position switch assembly allows engineers to set specific operational parameters quickly. Additionally, the unit features a rugged field wiring arm for secure cable terminations. This arm supports wire sizes ranging from 26 to 14 AWG. Mechanical keying pins ensure the module aligns correctly with the backplane pins during installation. These design choices simplify the setup process and reduce manual wiring errors.

Environmental Resilience and Certifications

This module performs consistently in challenging factory floor environments. It maintains operational integrity across a broad temperature range for global deployment. Moreover, the hardware complies with strict international safety standards to ensure workplace protection.

• Operating Temperature: 0°C to 60°C (32°F to 140°F)
• Storage Temperature: -40°C to 85°C (-40°F to 185°F)
• Relative Humidity: 5% to 95% non-condensing
• Compliance Certifications: CE, UL, and CSA
• Physical Dimensions: 3 x 14.7 x 26 cm

Reliability for Critical Automation

The 1785-BEM serves as a cornerstone for fault-tolerant PLC-5 architectures. It provides the necessary bandwidth for high-speed backup tasks in complex automation cells. Consequently, maintenance teams can swap processors without losing vital process state information. This module represents a proven solution for industries requiring maximum uptime and robust communication failover.