Before we start writing the scripts to control our alarm systems, it is probably a good idea to outline the high-level process for the system. The following flow-chart helps us picture how our system should work, and the various logical decisions our script needs to make.
The flowchart might look a bit complicated with all its lines in different directions, but it's actually pretty linear and in a downward direction. Referring to the flowchart, it shows the following tasks that the control script will be doing:
- Sitting quietly until the system is armed either by the hardware key switch or the web-based panel's soft switch.
- When the system is first armed, it will sound the exit buzzer for a pre-determined amount of time before actually arming the system. This gives you a chance to leave the property or disarm the system again, before it starts monitoring the inputs.
- Once the system is armed, the armed LED will be switched on and the system will wait to see if any of the alarm zone inputs are triggered. It will also wait to see if the alarm is disarmed on your return to the property. We can optionally put an entry timer in here on the entry zone to delay before triggering the alarm.
- If the alarm is ultimately triggered, then the main alarm bell will be switched on, as well as the exit buzzer. The main bell should only sound for a while, depending on environmental restrictions in your neighborhood, and so, this will be switched off after a pre-defined period, but the internal buzzer will stay on.
- When triggered, the system will then wait for you to disarm it, before resetting it.
The control script flowchart
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