Brief Product Description

Allen-Bradley 1785-CHBM is a ControlNet hot backup memory cartridge designed for Rockwell PLC-5 ControlNet processors. Providing 100K words battery-backed SRAM memory, this cartridge is installed in the memory slot of each redundant PLC-5 CPU, enabling program and runtime data synchronization between primary and standby controllers. Paired with 1785-BCM backup communication modules, it supports seamless automatic failover for critical control systems. It can also function as a standard memory cartridge for PLC program storage and backup. Built for industrial redundant control applications, it maintains program integrity and state data during controller switchover. Fully tested surplus and refurbished Allen-Bradley 1785-CHBM cartridges are available for legacy PLC-5 redundant system maintenance, memory cartridge replacement and plant automation retrofit projects.

Core Product Functions

• 100K words battery-backed SRAM for PLC program, tag and runtime state data storage
• Enable hot backup redundancy function for PLC-5 ControlNet series processors
• Continuous synchronization of control logic and process data between primary and standby CPU
• Cooperate with 1785-BCM backup communication module for fast automatic failover
• Preserve controller running state to realize bumpless transfer during CPU fault switchover
• Can work as standard memory cartridge to store and back up PLC-5 user programs
• Battery-backed memory retains program and data after power loss of the PLC processor
• Cartridge plug-in design for simple installation into PLC-5 processor memory slot
• Supports ControlNet network redundant control configuration for high availability systems

Application Scenarios

• Legacy Rockwell PLC-5 ControlNet hot backup redundant control systems
• Petrochemical and chemical batch reactor critical continuous process control
• Thermal power plant boiler, turbine and auxiliary safety interlock control systems
• Oil & gas, pulp & paper industries requiring zero-downtime process automation
• Critical manufacturing processes where unexpected shutdown will cause heavy losses
• Legacy PLC-5 redundant system memory cartridge replacement, maintenance and plant retrofits

FAQ (Frequently Asked Questions)

• Q: Redundancy synchronization failure or program loss after installing 1785-CHBM?
  A: Check backup battery health, verify matching firmware version of primary and standby CPU, inspect 1785-BCM module and communication wiring, confirm proper redundancy configuration in RSLogix 5 software.
• Q: Does Allen-Bradley 1785-CHBM support hot-swap replacement?
  A: Hot swap is not recommended. Back up PLC program and all parameters first, put redundant system into maintenance mode and perform lockout-tagout before replacement to avoid unexpected control switchover.
• Q: What PLC models are compatible with 1785-CHBM?
  A: It is designed for PLC-5 ControlNet processors such as 1785-L40C15, 1785-L80C15, requires paired 1785-BCM module for redundancy.
• Q: What is the memory capacity of 1785-CHBM?
  A: It features 100K words battery-backed SRAM memory.
• Q: Is Allen-Bradley 1785-CHBM available for new automation projects?
  A: This legacy PLC-5 hot backup memory cartridge is end-of-life for new installations. Only fully tested surplus and refurbished units are supplied for existing redundant system maintenance and retrofits.