getting signal from modem

I want to know how can I read from the modem it’s signal and “save” it in as global

I have found this post
http://forum.mikrotik.com/t/3g-modem-info-scripting/34329/1

and use this command I’m using

/interface ppp-client info interval=00:00:05 [find where comment=ISP1] do={:log warning $"signal-strengh"}
}

but it run all the time ,once every 5 seconds because of the interval , but I want it to run just for 5 seconds and close it , so how can I make this stop?
now the info is “locked” - and running on loop
so I can’t use the leds for showing the signal


Thanks,