Wanting to transmitt ASCII data when there is a process failure is normal. But wanting to transmitt it to a FAX machine is abnormal! You may be having specific reasons to do that, in which case it is not an easy thing.

First and foremost you need to know the Group number of the particular fax machine ( 2,3,4 etc - the manual of the machine will tell you this ) and then look up for technical information on the data format applicable. This the manual wont tell you. And herein your project stops.

Why not a small modem + serial printer + alarm that is controlled by another 8051 ? Printing or faxing will record the failure - but somebody also needs to know that there is a failure - so an alarm IS needed ?

Incidentally, TELEX killed TELEGRAMS.
FAX killed the TELEX.
And E-Mail has killed EVERYTHING!!

( The above is true in my company. Dont know about others)


Raghu