JOHNSON CONTROLS CARDKEY CK721 NETWORK CONTROLER 27-4805-05 BROKEN FROM SIDE#2

JOHNSON CONTROLS CARDKEY CK721 NETWORK CONTROLER 27-4805-05 BROKEN FROM SIDE#2

This unit is a Network Controller Panel from the Johnson Controls Cardkey CK700 Series access control and security management system. Its primary role was to serve as a critical communications hub and intelligent field panel within a hardwired, central-server-based access control system.

MODEL: CK721

MPN: 27-4805-5

MANUAL NO: 24-10025-8

ISSUE DATE: 05/05

VOLTS: 24VDC

AMPS: 24VA MAX

RY10704

Key Specifications & Features:

• Part Number: 27-4805-05. This is the specific factory part number for the main circuit board assembly of the CK721 controller.

• Model: CK721. This indicates it is a higher-capacity controller in the CK700 line, capable of controlling multiple doors, processing a large number of cardholders, and handling complex access rules.

• Architecture: It functioned as a standalone intelligent panel. It stored its own database of users and access schedules, allowing the doors it controlled to remain operational even if communication with the central computer was lost.

• Connectivity: It connected to the central system’s RS-485 data network (often labeled “Side 1” and “Side 2” terminals). The “Side#2” reference in your listing indicates the point of damage.

• Terminal Blocks: The board features robust screw terminals for connecting:

  • Reader Lines: For wiring card readers, keypads, and request-to-exit devices.

  • Lock/Relay Outputs: To control electric locks, door strikes, and other secure devices.

  • Inputs: For monitoring door position switches, alarm inputs, and other sensors.

  • Network (RS-485): Labeled “Side 1 IN” and “Side 2 OUT/IN” to daisy-chain multiple controllers on a single network loop.