Fax handshake needed?


hi there!

i would like to ask what is the AT command sequence for the fax handshake (if there is any…)…

anyway, i would like to describe below my set-up and procedures that i have done, and in hopefully you would be able to point me to some directions to move into…

Equip 1: Mobile Station (PC and Fastrack Supreme - Using mobile SIM with Data call support)
Equip 2: Landline Station (PC and Conexant Modem - Using a PSTN FAX number)

Procedure 1:

  1. From Equip 1 PC Hyperterminal, dial Equip 2 number “atd07xxxxxxx” .
  2. At Equip 2 PC Hyperterminal, “Ring” displays
  3. From Equip 2 PC Hyperterminal, type “ata” to to answer the call.
  4. “fax handshake” occurs, (i can hear the sound/noise when the modem tries to connect to each other)
  5. Equip 1 and Equip 2 are connected, so you can type characters from Equip 1 PC Hyperterminal and it is displayed in Equip 2 PC hyperterminal.
    –> Setup and Procedure 1 = OK.

Procedure 2:

  1. From Equip 2 PC Hyperterminal, dial Equip 1 number “atd021xxxxxxx” .
  2. At Equip 1 PC Hyperterminal, “Ring” displays
  3. From Equip 1 PC Hyperterminal, type “ata” to to answer the call.
    –> at this point i do not know what to do for the “fax handshake” to occur or for the modem to connect to each other…
    –> from Equip 2, i could still hear a tone beeping, i would guess that the Equip 2 is waiting for some command or identification from Equip 1…

i hope i explained my problem clearly…if you need more information, i would be happy to comply…thank you very much…


What does fax have to do with this?

you’re not sending faxes (ie, pictures), are you?

Just trying to establish a data call?


thank you for your reply.

yes you are right…I am just trying to establish a data call…i am sorry for the confusion…


can you please tell me how would i be able to establish a data call from my PSTN line (Equip 2-from the above) to my Mobile Station (Equip 1)…thank you very much…


Check with your GSM Service Provider, but you probably need a specific “Data Number” to establish an incoming data call to your GSM device…

Your Distributor should also be able to advise you on this…


i gave my GSM service provider a ring, and i was told that i would have the same “data number” for the incoming data call, and that the number that i am currently using would be able to handle both voice and data call.

i have mentioned in my earlier post, that i could hear a tone beeping from my equip 2 (Landline Station -PC and Conexant Modem - Using a PSTN FAX number-). anyway, i tried calling my mobile and my colleagues mobile using equip 2, and i was able to hear the same tone from my mobile. i reckon, it would be the data (fax) number waiting for an identification or some confirmation from the receiving number…

do you have any thoughts that i could try to work on… i have been searchin this forum and the web for some and i was not successful so far…i also have read and re-read the documents that i have downloaded from the wavecom website but still i came up short…i would appreciate much if you could give me headstart…thanks…


I’m sorry, I find your “equipment 1” and “equipment 2” confusing - it’s just an unnecessary level of indirection.

Please can you describe again what you’ve tried naming the equipment directly as “Fastrack” and “PSTN modem”, etc…


Where are you doing these tests?
What operator(s) and network(s) are you using?

See also: viewtopic.php?f=34&t=1622


thanks for your reply…

below is a step by step process of what i am trying to do.

  1. From the PSTN Modem dial the Fastrack Modem number.
  2. In the Fastrack Modem a “RING” is displayed
  3. In the Fastrack Modem answer the call “ATA”
    –> at this point, no data connection is established.
    –>i can still here the tone beeping sound from the PSTN Modem.

i have also tried all the bearer type selection values, i.e. at+cbst= 1,0,1; at+cbst=7,0,1, etc… but still i cannot establish a data call connection.

i am from New Zealand, the PSTN operator is Vodafone, and i am also using Vodafone pre-pay SIM.

hope to hear from you…thank you very much…


Try AT+CRC=1 - then you should get an indication of whether the Fastrack thinks its a voice or data call coming in…


Fastrack Modem displays: +CRING: VOICE

does it mean that my Vodafone pre-pay SIM is not data enabled?


Maybe; maybe not.

I don’t know how your networks work down there, but up here they (including Vodafone) assign separate numbers for voice and data.

I think you really need to find a local Wavecom distributor to advise you on this - if your networks are anything like ours, you stand no chance of getting anything useful out of their customer helplines. :angry:
See: viewtopic.php?f=34&t=1106

Or perhaps you could find a specialist M2M service provider…?


thanks for your reply mate…i gave Vodafone customer helpline another ring to ask why is it that i cannot accept data call from my pre-pay SIM card considering that i was told that i should be able to do so…anyway, lo and behold, i was told that for the pre-pay SIM card, data call is not available, and that they do not provide data numbers for pre-pay SIM card…what a waste of time trying to figure out what was wrong in what i have been trying to do…

anyway, i am now trying to find an economical way of acquiring a SIM card with data call (i.e. with separate data number)…i will keep you posted for any development…