Battery and Key Switch Module Honeywell FC-BKM-0001

Product Description

The FC-BKM-0001 is a specialized utility module for the Honeywell Safety Manager (SM) controller rack. This dual-function module ensures memory integrity during power interruptions and provides a physical security interface for controller state management. As a core component of the central processor assembly, it preserves safety logic, configuration data, and sequence-of-events (SOE) records under all operating conditions.

The module features an integrated battery backup to maintain volatile memory (SRAM), preventing loss of critical application logic during unexpected power loss. Its front-panel key switch adds an essential layer of physical security, allowing authorized personnel to toggle controller operating modes (RUN, PROGRAM, FORCE) and preventing unauthorized modifications to the Safety Instrumented System (SIS).

Technical Specifications

Security and Reliability Features

• Physical Access Control: Mechanical key switch prevents unauthorized software-level modifications, supporting cybersecurity and safety compliance.

• Data Persistence: Enables “warm start” after power interruptions, reducing downtime and avoiding manual logic reloads.

• Hot-Swappable Battery: Battery can be replaced without disrupting active safety logic when the system is powered.

Technical FAQ

What happens if the battery fails?
The system triggers a diagnostic alarm (e.g., “Battery Low” or “Battery Fault”) on the HMI and controller LEDs. While the system continues running on active power, a failed battery risks loss of unsaved application data and SOE logs during a subsequent power loss.

Does the key switch lock out remote software changes?
Yes. When set to RUN, the key switch typically restricts remote forcing of I/O points or logic downloads from the engineering workstation, preventing accidental or malicious changes.