Issue
How to sound a buzzer when a Request To Exit (REX) button is pressed on a Continuum Access system? The inputs to a door are not defined as regular Infinity inputs so how can they be programmed by Plain English programming?
Environment
ACX57xx (ACX5740, ACX5720) and AC-1 IOU modules (AC-1, AC-1A, AC-1 Plus)
Cause
When engineering an access control project, there is sometimes the requirement to sound a buzzer or turn on a light when the door is unlocked, or when a Request To Exit button is pressed, as the input points used within the door object configuration are not defined as a regular Infinity Inputs, so how to achieve this functionality?
Resolution
To use a Request To Exit (REX) switch on any of the ACX controllers or AC1 Modules:
- It has to be a supervised input wired with the appropriate resistors in one of the 6 standard configurations defined in the installation guides (All available on the Extranet).
- You can not use a simple digital input switch without resistors.
- Incorrect circuitry or missing resistors will result in a Trouble indication on the door.
- The REX input is not a regular Continuum input point as it is defined within the door configuration, as it is not a Infinity input point directly accessible from Plain English but can be read via the "ExitRequest" attribute of the door.
To sound a buzzer from the from the door there are 3 options:
- Use the existing door output and slave a buzzer circuit from the output that drives the Magnetic lock, so will sound when the door unlocks.
-
If you want the buzzer to sound when the REX button is pressed then use a button with a 2 pole switch (2 separate contacts):
- Wire one to the REX input with appropriate resistors.
- Wire the other switch to a spare Input
- Configure it as either a Digital input or a Supervised input with resistors.
- This point can be used in your PE programming to drive the buzzer output.
- The third option is to use a Plain English program to read the "ExitRequest" attribute of the door and turn on an output for a defined time. The ExitRequest attribute may only be on for a short period of time so the program must be constantly looking for this attribute to change as well as keeping the controller Scan time low.