limonce@pilot.njin.net (Tom Limoncelli) (08/21/88)
I'm writing an answer-the-phone routine for my current project. The
modem will be hayes compatable but I have to be able to handle various
almost-hayes compatable modems.
When answering the phone, I wait for "CONNECT" or "CONNECT 1200" but
when should I expect the CD to come on? (where in the "CONNECT"
message... beginning, end, etc) Is it different for various modems?
Any other tips for generic answer-the-phone routines?
Tom Limoncelli
--
Tom Limoncelli -- Drew University, Box 1060, Madison, NJ 07940
TLimonce@Drew.Bitnet -- limonce@pilot.njin.net -- VoiceMail (201)408-5389
Drew College of Liberal Arts: male/female ratio: 2:3 student/pc ratio: 1:1
"The opinions expressed are mine... just mine."james@astro.as.utexas.edu (James Van Artsdalen) (08/27/88)
In article <telecom-v08i0131m03@vector.UUCP>, limonce@pilot.njin.net (Tom Limoncelli) wrote: > When answering the phone, I wait for "CONNECT" or "CONNECT 1200" but > when should I expect the CD to come on? (where in the "CONNECT" > message... beginning, end, etc) Is it different for various modems? Yes it varies. The better modems appear to follow this sequence. The CONNECT message is printed, possibly indicating the modem-to-modem data rate. Carrier Detect is *then* asserted, and the modem then switches its data rate between then local machine and the modem if appropriate. I have however observed an older US Robotics Password to assert carrier detect *before* printing the CONNECT message. I'm not sure how standardized the behavior is after hangup. My Trailblazer is configured to switch back to 9600bps, though I don't believe it normally does so. I believe most stay at the last connected rate. The last common gotcha is that some modems will fail to fall "up" on answer. If there last call was at 1200bps, the modem will not answer at 2400bps but only 1200bps... -- James R. Van Artsdalen ...!uunet!utastro!bigtex!james "Live Free or Die" Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746