How to extend analog line using VoIP with SPA8800

Question

I would like to use a SPA8800 to make an analog line available to a VoIP phone (because at the location of the phone only LAN is available and no phone line). This is, when the line rings, the VoIP phone should ring. It would be nice to have if the VoIP phone could also use the line to dial out.
I already have the SPA8800, furthermore I have a SPA941 phone.
PSTN ----- line ----- SPA8800 ----- Ethernet ----- SPA941
Can you give advice on the necessary configuration for the SPA8800 for this setup? The few guides I could found were all for the other way around (Internet ----- SPA8800 ----- analog phone).

Answer 1

Sastra;
If the trigger signal you need is TTL type, you can use one of the general purpose counters available at the board to do that.
You just need to configure the counter to do retriggerable single pulse generation, and have the reference signal that clocks the analog inputs routed to the gate of that counter. That will generate a pulse at the event of an active edge at the counter gate.
Hope this helps.
Filipe A.
Applications Engineer
National Instruments