JOHNSON CONTROLS CARDKEY CK721 NETWORK CONTROLLER 27-4805-05 BROKEN FROM SIDE

JOHNSON CONTROLS CARDKEY CK721 NETWORK CONTROLLER 27-4805-05 BROKEN FROM SIDE

Product Identification

• Manufacturer: Johnson Controls (acquired Cardkey, a legacy brand in physical access control).

• Model: CK721

• Type: Network Controller / Panel

• Part Number: 27-4805-05

• Condition: Broken from the side (likely physical housing damage).

• • VOLTS: 24VDC

  • AMPS: 24VA MAX

  • FUSE: NA

Primary Function

The CK721 is a hardwired, intelligent field panel that forms the backbone of a Cardkey access control system. It is the “brains” at the door level, managing access decisions, monitoring alarms, and communicating with the central server/software.

Key Features & Technical Details

• Standalone Intelligence: Stores user access credentials, door schedules, and alarm parameters. Can operate doors and make access decisions even if communication with the central computer is temporarily lost.

• Reader & Door Interface: Typically connects to 1 or 2 doors (controls 1 or 2 readers and their associated door hardware like locks, exit devices, and door position sensors).

• Inputs & Outputs (I/O): Includes a number of supervised input points (for monitoring alarms, request-to-exit sensors, etc.) and output relays (to control locks, signals, or other devices).

• Network Connectivity: Connects to the host computer/server via a RS-485 communication line (often labeled “NETWORK” or “COMM”), which is daisy-chained to other panels and connected to a network interface module.

• Power: Requires a separate 12-24VDC power supply (e.g., a Cardkey CKP-12/24 or equivalent). The part number you have is for the controller board itself, not the power supply.

• Memory Capacity: Legacy systems like these often had capacities for several hundred to a few thousand cardholders, stored in non-volatile memory.