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modem

Modem escape sequence (+++) passed as data

one question regarding modem, Hayes escape sequence. First to explain what is happening:

==> ATD 123\r\n
<== +CR: REL ASYNC\r\n
<== CONNECT 9600\r\n

After this moment I have online session. When I want to hangup, I am doing next.
< no data 1.5 seconds >
==> +++  (no \r\n)
**+++ is received on destination side (why?)**
<== OK
< no data 1.5 seconds >

==> ATH\r\n
<== OK
Destination side gets NO CARRIER.

The problem for me is that escape sequence is received as regular data on destination side. Does anyone have an idea what should I do? Some modem configuration tweak?

Thanks!

Solution

  • I will answer my question. I did not find the way to do that.

    Instead, in order to hangup I use DTR (Data Terminal Ready) signal. After switching from active to inactive, the other side determines that as hangup (if modem is configured with AT&D2).