ANNOUNCE: Using X100P Cards As FXS Devices

Standard X100P cards are normally used as FXO devices. FXS devices (devices which allow you to plug in a standard telephone set) are of course available but are more expensive than FXO cards. This hack enables you to use the X100P (and clone) cards as FXS devices, subject to certain limitations:

  • You must supply an external power source (12 V DC)
  • The present version of the hack does not support ringing
  • Some users have reported problems when using DTMF (tone) dialing. Rotary (pulse) dialing works well.

This hack requires you to make both software and hardware changes. You must download and apply a software patch to the asterisk zaptel (wcfxo) driver. In the simplest case, the hardware changes require only wiring changes - no other additional hardware components are needed (aside from the wiring and connectors).

For further information please go to

do you think it’s possible to do a tihng like this with a FXO modul on a TDM4000 card?
Anyway, GREAT!

Conceptually there should be no problem in extending this to the TDM400 FXO module. The present version offers a patch to the X100P module only (wcfxo.c), and it would be necessary to apply a similar modification to the TDM400 driver module (wctdm.c).

If someone wants to send me a sample of the hardware for testing, I’ll get right on it :slight_smile:


I’m considering to buy a tdm2400…
send me your address and maybe Santa Claus will bring to you my old tdm400…