rgh@mtunf.ATT.COM (Ronald Hiller) (08/13/89)
Hi, I am trying to connect an AT&T 2224 CEO modem to an IBM PC clone. I currently have a Hayes Smartmodem 1200 connected and thought it would be a simple matter to unplug the Hayes and plug in the 2224. Turns out it isn't that simple. The 2224 responds correctly to the commands sent to it (via CTRM software) and will dial and everything, but I don't get any of its ouutput back to my PC. CTRM has a mode where it will show communication errors and, if I turn that on it says that I am getting framing errors. I have tried every possible combination of Parity/Stopbits/baudrate with no success. I have also tried different cables, ranging from a 4 conductor (TX, RX and 2 ground) to a full 25 conductor cable. These problems convinced be that the modem must be at fault, but then I connected the 2224 up to my UNIX-PC and it works like a charm (I guess it likes AT&T equipment!). In desparation, I connected a HP Protocol analyzer in the line and it shows the 2224 sending stuff out just as it should. Then, I tried to use the protocol analyzer in "Simulate" mode. The PC gets framing errors from it as well, and if I connect it to the UNIX-PC, the characters come out as they should. Now, I believe it is my PC that is at fault. I have tried several software packages with no luck, but I still can't understand why everything works properly with the Hayes modem and with a couple of other modems and printers I have. How can I get things working??? Please e-mail responses if possible, Thanks in advance Ron Hiller ...!att!mtunf!rgh rgh@mtunf.ATT.COM