Issue
Using a Door's Card Reader to Inhibit and Enable Alarms
Product Line
TAC I/NET
Environment
I/NET
Cause
Access Initiated Control (AIC) can be used to trigger points based on reader entry. This is triggered regardless of if the door is open or closed.
Also, when using multiple commands, such as inhibit/enable alarms, one would need multiple readers to trigger the points. The following process allows you to use the same reader to trigger both the enable, and inhibit alarm function.
Resolution
Create Points:
- If you have not done so yet, build a point for the Door Status.( These directions assume that 1= Open and 0 = Closed)
- Build an internal point called AIC Trigger.
- Create a calculation that keeps this point in the off state
Configure AIC
- Create an AIC that will turn the AIC Trigger point on with a reader entry
- Assign this AIC to the appropriate door
Create Event Sequences
- Create an event sequence called Enable
- Create an event sequence called Inhibit
- Modify the Inhibit event Sequence
- Add lines that will Inhibit each alarm
- For the last line, set a delay equal to the strike duration and the type as Skip if non-Zero
- Set the point as the Door Status and the Sequence as the Enable Sequence #
- Click OK
- Modify the Enable sequence
- Add lines that will Enable each alarm
- Click OK
- Click close
- Select Edit>Controller>Point Extensions>Event Definition
- Double Click on the AIC Trigger Point
- Set the Event type to Specified State
- Select "Sequence" and set the sequence number as the Inhibit sequence
- Select the State/Value as On
- Click OK
Results
- Entering the door with a valid card read will cause all alarms to go to an inhibit state
- After exiting the door and allowing it to close, one can scan a card to enable the alarms. This will take effect after a delay equal to the strike duration.
- This process is based on the door position switch being open or closed as the strike duration expires. So that arming the system will only occur if the door is closed.
- There is a potential flaw if someone is able to scan a card, enter the room, and close the door before the strike duration expires. If this happens the system will re-arm itself as the strike duration expires. For this reason, it is important to have as short a strike duration as possible.