Appendix F - Pre-Alert Relay; Pre-Alert; Table 27 - Pre-Alert Relay To Door Assignments - Keyscan CA250B Technical Instructions

Appendix F – Pre-alert
Relay
The optional pre-alert relay advises when a door remains open at the half interval of the combined door relay
unlock time and door held open time in the Client software. Reader will also sound on an alarm tripped. This
function is a feature within the control board and may be wired to an external device. To use the Pre-alert
relay option on CA4500B or CA8500B control boards, an additional OCB-8 is required.

Pre-alert

Depending on the number of doors and type of controller, ensure that the pre-alert relay on the output control
board matches the correct door contact as indicated in the following table.
Control Board/OCB-8
CA250B/OCB-8
CA4500B/OCB-8 (optional)
CA8500B/OCB-8 (optional)
Important
All relays on the OCB-8 board are dedicated as pre-alert output relays when used on the CA8500B circuit
board.
The pre-alert relay is also activated on an "alarm tripped".
Keyscan Inc. – Technical Guide (PC109x - 04.15)
Table 27 – Pre-alert Relay to Door Assignments
Pre-alert Pre-alert
Outputs Relay # on
OCB
2 Relay 7
Relay 8
4 Relay 5
Relay 6
Relay 7
Relay 8
8 Relay 1
Relay 2
Relay 3
Relay 4
Relay 5
Relay 6
Relay 7
Relay 8
Door Ribbon Cable Connection
Contact
#
Door 1 Connect ribbon on OCB-8 to control
1 on CA250B
Door 2
Door 1 Connect ribbon on OCB-8 to control
2 on CA4500B.
Door 2
(Relays 1 to 4 for Auxiliary Outputs
Door 3
5 to 8.)
Door 4
Door 1 Connect ribbon on OCB-8 to control
3 on CA8500B.
Door 2
Door 3
Door 4
Door 5
Door 6
Door 7
Door 8
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