Allen-Bradley 1785-BCM Backup Communication Module

Overview

The Allen-Bradley 1785-BCM is a Backup Communication Module designed for PLC-5 processors. It ensures high-speed data transfer and redundancy between two PLC-5 controllers, providing continuous operation in case of processor or communication failure. Typically deployed in critical control systems, the module automatically switches control to a standby processor when a failure in the primary processor is detected.

Technical Specifications

• Manufacturer: Rockwell Automation
• Catalog Number: 1785-BCM
• Product Type: Backup Communication Module
• Platform: PLC-5
• Supported Processors: PLC-5/15 Series B, PLC-5/20, PLC-5/25, PLC-5/30, PLC-5/40, PLC-5/60
• Communication Type: High-speed parallel data transfer
• Redundancy Mode: Automatic switchover upon failure detection
• Slot Requirement: Single-slot module
• Compatible Modules: 1785-BEM (Backup Expansion Module)
• Required Chassis: Local chassis with power supply
• Network Compatibility: Data Highway Plus, Remote I/O
• Software Requirements: 6200 Series Software

Key Features

• Provides redundancy between two PLC-5 processors
• Automatic switchover ensures minimal downtime
• Supports Data Highway Plus and Remote I/O networks
• Compatible with 1785-BEM for full backup functionality
• Designed for critical applications requiring high availability

Common Questions

• Q: What is the primary function of the 1785-BCM?
  A: It provides backup communication and automatic switchover between two PLC-5 processors to maintain system continuity.
• Q: Is the 1785-BCM compatible with all PLC-5 processors?
  A: No, it supports specific models including PLC-5/15 Series B, -5/20, -5/25, -5/30, -5/40, and -5/60.
• Q: What additional modules are required for full redundancy?
  A: The 1785-BEM (Backup Expansion Module) is typically used alongside the 1785-BCM.
• Q: Can the module be used in remote I/O systems?
  A: Yes, it supports both Data Highway Plus and Remote I/O networks.