Interlocking Doors - Interlogix CDC4 Installation And Programming Manual

Chapter 2: System functions

Interlocking doors

Interlocking is a method that stops two or more doors from being opened at the
same time. Interlocking may be used in a vault, for example.
When programming a door on CDC4, there are two ways to specify an interlock
door: either another door on the same CDC4, or a door on a separate controller.
Interlocking doors on the same controller
CDC4 has simplified configuration of interlocking doors on the same controller.
When programming the door, navigate to the door "Hardware tab" described on
page 97 and select the required interlock doors in the Interlock doors list.
When an attempt to open/unlock the programmed door occurs (either from user
action or from management software), CDC4 will check all other locally linked
doors to ensure that no other door is unsecure, before allowing the door to open.
When internal interlocking option is enabled on CDC4, a special interlocking
timer (300 ms if only internal interlocking is enabled) is started when a user
credential is presented. Any repeated attempt to gain access by providing a user
credential while the timer is running and the remaining time is greater than
100 ms will cause Access Denied Void and 7 error beeps. If access is granted
and the door becomes in access, this waiting time is bypassed and all the
consequent credential requests are processed without that delay.
A proposed sequence of user action on the interlocked doors is below:
1. Present a credential (hear a single beep if it is a card, or press Enter if it is
a PIN).
2. Wait for CDC4 to confirm. CDC4 confirms with either 2 beeps if the credential
has a right to access or 7 beeps in case of a wrong credential. The waiting
time may be less than a second if no external interlocking is enabled or about
3 seconds if external interlocking is enabled.
3. Proceed to the next step.
Interlocking is programmed on the "Hardware tab" of the Doors form. See the
"Interlocks" section on page 98.
Interlock door on external controller
There are three external input fields provided for CDC4 to check for interlocking
on external controllers.
To interlock with a door on an external controller, a contact from the external
door must be wired to a spare input connected to CDC4, and vice versa.
When programming the door on CDC4, navigate to the door "Hardware tab"
described on page 97 and define the locations of the inputs connected to
external door contacts in the External input fields.
When an attempt is made to open/unlock the programmed door (either by user
action or from management software), then CDC4 will check the state of these
52 CDC4 Door Controller Installation and Programming Manual