JOHNSON CONTROLS CARDKEY CK721 A NETWORK CONTROLLER 27-5379-714 BROKEN FROM SIDE#2

JOHNSON CONTROLS CARDKEY CK721 A NETWORK CONTROLLER 27-5379-714 BROKEN FROM SIDE#2

Product Description: Johnson Controls (Cardkey) CK721 Network Controller

Model: CK721 (also found as CK-721 or P/N 27-5379-714)
Condition: USED– Unit is physically broken/cracked on Side #2 (see photos). Sold as-is for components, board-level repair, or advanced troubleshooting.

Core Function:
The CK721 is a high-performance, microprocessor-based Network Controller designed for the Cardkey (now Johnson Controls) P2000 and System Galaxy access control and security management systems. It acts as the central “brain” for a group of doors, communicating between the host PC/server and the downstream field hardware.

Key Features & Specifications:

• Architecture: Serves as the primary communication hub for a network of field panels (e.g., CK721-C, CK703 readers, etc.) within its defined branch.

• Processing Power: Manages cardholder databases, alarm monitoring, and event logging for its entire branch independently, providing distributed processing to reduce host load.

• Communications:

  • Host Communication: Connects to the host computer/server via RS-422 multi-drop network (typical for P2000 systems) or can be configured for other protocols.

  • Field Communication: Connects to downstream Cardkey field panels and hardware via its terminal blocks.

• Memory: Contains robust non-volatile memory to store cardholder data, access levels, time zones, and alarm point configurations for its assigned branch.

• Inputs/Outputs: Provides supervised alarm inputs and relay outputs for controlling locks, gates, and other security devices across the branch.

• LED Indicators: Status LEDs for Power, Network Activity, and System Diagnostics.

• Power: Requires a dedicated 24VAC or VDC power supply (not included).

Typical System Application:
In a Cardkey P2000 system, the CK721 sits between the host PC and the door-level controllers. A single host can manage multiple CK721 Network Controllers, each controlling a separate building, floor, or branch of the system, allowing for large, scalable installations.

Important Notes on This Specific Unit (27-5379-714):

1. Physical Damage: This unit has sustained significant physical damage to its housing on Side #2. This likely compromises the structural integrity and may have caused internal damage to the PCB, connectors, or components. It is not a plug-and-play operational unit.

2. Part Number: 27-5379-714 is the specific factory part number for the complete CK721 controller assembly.

3. Use Case: This unit is ideal for:

   • Technical Repair: A technician needing a donor board for ICs, processors, memory chips, or other surface-mount components.

   • Harvesting Connectors & Hardware: The terminal blocks, screw terminals, and housing components may be salvageable.

   • Diagnostics/Training: For advanced troubleshooting practice or as a visual training aid for system wiring.