I used to work with Rockwell for many years. I'll see if I can dig up some more information, like AT commands needed, the correct sequence, correct timing and maybe some 'C' source code.

Anyway, here is a basic description so you can get an idea:

I assume the 8051 is connected to a fax modem through the serial port and is the only "intelligent" part in your system.

First of all there are two different AT command "classes" for this. The difference is the amount of work the host (in this case the 8051) has to perform.

Secondly, the image is compressed using TIFF format. If you are just passing along a "canned" message it is straight forward. Otherwise you have to convert your ASCII string to a bitmap and then compress it using the TIFF algorithm before sending it out.

I guess the compression has to be done beforehand as the modem requires a constant stream of data from the host, once the image transmission has commenced. During this period handshaking is off, so timing is critical.

I think it's doable, but a tight squeeze to get the fax transmission sequence embedded.

As I said, let me go home and check what I can dig up.


Jesper