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May FSK signals be used to receive a signal about

Started by dsk, October 01, 2013, 12:09:49 PM

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dsk

May FSK signals be used to receive a signal about when the called party answers?

I don't know much about FSK, but the need of a detection of answer are still there since polarity reversal are history.
An advanced payphone controller should be able to do a lot with this information, Start the collecting, break the line when the other ends hanging up etc.

dsk

PS USA/Europe use different frequencies for FSK  ???

G-Man

The only Frequency Shift Keying (FSK) signals currently used in the U.S. PSTN are for Caller ID (CID) signaling.

poplar1

FSK signaling is also used to activate/deactivate Visual Message Waiting on POTS lines.

http://tesmw.com/
"C'est pas une restauration, c'est une rénovation."--François Martin.

kb3pxr

Assuming you aren't on a POTS line, I'd recommend doing this signaling outside the voice band or disabling the transmitter until this signal is received combined with disabling the FSK detector until disconnect or forward disconnect is received.

Now obviously this isn't going to be a public pay phone, but the last thing you want is to try demonstrating acoustic coupler modems and cause interference with your supervision system.

HarrySmith

Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Sigmaz


AE_Collector

But, unlike many new posts to very OLD topics, this time the OP (dsk) is still here actively on the forum.

Terry