Results 1 to 4 of 4

Thread: Not receiving trunk events

  1. #1
    schellens Guest

    Default Not receiving trunk events


    My application is interfacing with a Daytona Analog HMP PCIe 16T board.
    The intension is to log POTS phone-lines in passive mode.
    Therefore each trunk channel is connected in parallel with a phone-line.

    Besides passive logging of the phone-line, I am also interested in detection of some phone protocol events, i.e. on/off-hook and on/off-ring events. It is the reception of those events that malfunction:
    1. No trunk on/off-hook events are received.
      Are these events only generated as response on a SetHookSwitch command?
    2. Only sometimes ring-on/off events are received while the phone is ringing.
      The ringing signal is generated by a company phone system. The ring signal is about 100 Volt top-top, with an average voltage of 0 Volt (so a pure AC-signal).
      Why is not each ring signal preceeded by a ring-on and terminated with a ring-off event?
    Thanks for any answer(s).

  2. #2
    Join Date
    Jul 2008


    Hi schellens,

    When connected directly to the telco SetHookSwitch is the only way to exercise on/offhook.

    As for the failure to get the expected trunk events when logging, have you made sure to set the line threshold correctly? I suspect this could be the problem. Specifically - to use the board in a passive logging scenario it is necessary to use the PKH_TRUNK_SetThreshold function and set either PKH_TRUNK_THRESHOLD_24V_LOGGING or PKH_TRUNK_THRESHOLD_48V_LOGGING depending on the line.

    In aohtest I think the command should be:
    "trunk 0-15 set threshold <value>" where normal=4, 24V=16 and 48V =33
    Last edited by mrecoskie; 06-30-11 at 01:30 PM.

  3. #3
    schellens Guest


    Hi mrecoskie,

    Indeed the use of threshold passings (in my case THRESHOLD_48V_LOGGING setting) also works to detect on/off-hook changes. I just was wondering why the "real" on/off-hook events are not received in passive logging mode.

    Any ideas about the inconsequent reception of ring-on/off events?
    May the absence of a 50V bias-voltage (only a pure AC voltage is generated) be the reason?
    In fact I receive a lot of REVERSAL events when the ring signal is generated.

    Jan Schellens

  4. #4
    Join Date
    Jul 2008


    The absence of a bias voltage should not be a problem. Is it possible to list the events you are receiving and their timings?

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts