That's one of the scripts that I wrote!
The general idea of this script is to track all targets to look for ARMyness (e.g. going straight towards the SAM at high velocity).
To accomplish this, the detected missile event is fired whenever a missile target is identified or has its position updated. By saving the history of a given target, this event can then estimate the speed and direction of the missile, and will compare it (using the decide function in the CHANGE ME section) to the position of all SAM-side units. If the missile is travelling at sufficient velocity in the direction of a SAM site, the SAM site will then be set to off-air, and will have its identity added to another list, which will put it back on air after a specified interval.
This was written many, many versions ago, so there's better ways to do much of this now. However, to adapt it to a scene, all you *should* have to do is adjust the "samside" field in the CHANGE ME section of the "detected missile" action. The rest should work out-of-the-box, though there may be an issue with the SAM side's missile shutting down its own radars.
JOOC, how does a SAM operator detect an inbound HARM?
In this case, there's no fancy anti-anti-radiation detectors, it's just looking for a really fast thing passing within a km or two of the SAM site.