FC-BKM-000 HONEYWELL Battery and Key Switch Module new

• Brand
  HONEYWELL
• Model
  FC-BKM-000
• Product Name
  Battery and Key Switch Module
• Place of Origin
  United States
• HS Code
  85371011
• Dimensions
  176 mm × 35.2 mm × 224 mm
• Weight
  0.66 kg
• Operating Temperature
  ‑5 °C to +70 °C
• Storage Temperature
  ‑40 °C to +85 °C
• Power Supply
  24 V DC
• Warranty
  12 month
• Product Status
  New and original

Honeywell FC-BKM-0001

Input Specifications

Power Supply Input: Nominal 24 VDC power input, operating tolerance -15% ~ +30%; typical operating current 7 mA, maximum input current 20 mA. Auxiliary 5 VR power input: 5 VDC ±10%, maximum input current 10 mA.

Backplane Interface Input: Dedicated backplane bus signal input for data interaction with Safety Manager CPU module.

Manual Key Input: Two physical key-switch inputs used for fault log reset and I/O forcing enable operation.

No external analog field input and no external digital field input channels are available.

Output Specifications

Backplane Bus Output: Transmits backup battery status, key-switch position and module diagnostic information to CPU through rack backplane.

Battery Backup Output: RAM backup power output voltage range 14-31 VDC; parallel output resistance approximately 2×1.1 kΩ, built-in short-circuit protection function.

Diagnostic Indicator Output: On-board LED indicators display power supply operating state, battery health condition and key-switch position status.

No field-side analog output, relay output or digital output channels for driving external field actuators.

Honeywell FC-BKM-0001 Working Principle

The FC-BKM-0001 serves as a battery and key-switch auxiliary module for the Honeywell Safety Manager safety system. It is installed on the controller backplane and communicates with the CPU over the rack bus, with no external field-level I/O channels.

Backup Power Supply Principle: This module incorporates two non-rechargeable lithium batteries. While the rack main power sources (24 VDC and 5 VR) operate normally, the module monitors battery voltage without drawing power from the batteries. Upon main power failure, the lithium batteries deliver 14-31 VDC backup voltage via a short-circuit-protected circuit. This backup power sustains the controller RAM, real-time clock, historical fault logs and network address data to prevent loss of system status information during power outages. The internal lithium batteries provide roughly three months of cumulative backup runtime. An integrated battery switch can disconnect battery output for long-term storage or transportation.

Key-switch Signal Processing Principle: Two mechanical key switches, namely the Force-Enable switch and Reset switch, translate manual key operations into electrical level signals. Switch status is transmitted to the Safety Manager CPU through the backplane bus. The Force-Enable switch governs hardware authorization for I/O forcing; maintenance staff can only execute forced-override operations on safety-related I/O channels when this switch is activated. The Reset switch performs hardware-level clearing of fault log entries. Every key-switch operation is logged within the system fault history to support audit and traceability.

Diagnostic Monitoring Mechanism: The module continuously samples main supply voltage, auxiliary 5 VR voltage and internal battery voltage. If battery voltage falls below threshold values or power supply anomalies are detected, diagnostic fault signals are sent to the CPU via the backplane bus, and onboard LED indicators display power operating condition, battery health and key-switch position. A short-circuit protection circuit activates automatically in case of output short-circuits to protect the internal batteries from damage.

Backplane Bus Interaction: The module draws 24 VDC and 5 VR auxiliary power from the rack backplane. It uploads battery health status, key-switch position and module fault information to the CPU across the backplane bus. The CPU determines whether I/O forcing is permitted based on key-switch state and triggers low-battery alarms to upper-level monitoring systems. Hot-swap capability is supported; removing the module will automatically terminate all active I/O forcing operations so as to preserve the safety of safety-critical control loops.
FX-USI-0002
CC-PCNT02
FC-QPP-0001
FC-SCNT01
FS-USI-0002
FC-QPP-0002
51198685-100