[asterisk-users] Analog FXO status checking

[François Delawarde]

Hi all,

I would like to make a script/program that would be able to show lots of 
status information from my analog FXO lines (and FXS lines in the near 
future).

Example of interesting status information:
- Hook status: is there a call being made with that zap?
- Voltage status: cable connected, voltage values (if possible), line 
ringing?
- RX/TX Volume status

I'm using a TDM400 card with FXO modules plugged on spanish lines, and 
trying to parse "zap show channel X" with Asterisk 1.4.0 gives me 
unexpected results:

- "Hookstate (FXS only)" line shows Onhook when cable is disconnected 
and Offhook when cable is connected, whether there is a phone call or 
not... Is it normal (with an FXO line)? Can someone explain me why?

- The only way i found to know if the line is in use is to check the 
"Echo Cancellation" line which shows "currently ON"... Is there another 
way without having to parse "core show channels concise"?

- No volume information, voltage status or anything.

Would it be possible to check status of those lines (with voltage info, 
...) making a program that would read information from "/dev/zap/X" 
character devices (ioctl?) without having to stop asterisk ("/dev/zap/3: 
Device or resource busy" when asterisk is running)?

Thanks in advance for anyone that could help me!