notifications on radio silence

Following a conversation with B, I thought about ways to detect silence when SGH goes off the air on AsiaStar, and using the parallel port for detecting silence and so on. P came up with the Restless Winamp plugin to be installed at the playout server. We did that, and modified the C:\Documents and Settings\User\Application Data\Winamp\winamp.ini file by adding
[Restless Winamp Plugin]
Hit_Start_After_Millis=30000
Hit_Start_After_Minutes_Seconds=00:30

P then suggested using the sound card instead for silence detection, and immediately found the Piraside Silence Detector - software which does this very job! Hooking up a modem to the machine can then make it dial P or me when the silence is detected. But it does not work as easily as given on it's home page - a bat file with commands sent to COM1 etc don't work under WinNT or above. XP etc do not allow direct access to hardware from the Command Prompt, unlike DOS. After tests with hyperterminal etc, the solution of choice is currently autoit - using a user dll and control script to send AT commands to the modem. Just simple ATDT to dial the number, using a ProcessWait to wait for a while, ATH to hang up and so on.