[ntp:questions] ACTS / PTB modem refclock

Uwe Klein uwe_klein_habertwedt at t-online.de
Wed Apr 25 07:21:05 UTC 2007

Danny Mayer wrote:
> Heiko is trying to do this from Germany so it would need an additional
> international dialing code, with possible pauses required for modem
> synchronization. Who knows what else is going on.

>>Heiko Gerstung wrote:
>>>I am currently trying to setup a box which uses the ACTS refclock driver 
>>>to use the PTB modem service as a time source.

I thinks "B1 : US answer tone" is the culprit.

<from refclock_acts.c>
  * Modem setup strings. These may have to be changed for some modems.
  * AT   command prefix
  * B1   US answer tone
  * &C0  disable carrier detect
  * &D2  hang up and return to command mode on DTR transition
  * E0   modem command echo disabled
  * l1   set modem speaker volume to low level
  * M1   speaker enabled until carrier detect
  * Q0   return result codes
  * V1   return result codes as English words
#define MODEM_SETUP     "ATB1&C0&D2E0L1M1Q0V1\r" /* modem setup */
#define MODEM_HANGUP    "ATH\r" /* modem disconnect */

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