Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!uwm.edu!lll-winken!telecom-request From: hayes!tnixon@uunet.uu.net (Toby Nixon) Newsgroups: comp.dcom.telecom Subject: Re: Can You Disable Call-Waiting AFTER the Call Starts? Message-ID: Date: 19 Mar 91 13:03:36 GMT Sender: Telecom@eecs.nwu.edu Organization: Hayes Microcomputer Products, Norcross, GA Lines: 34 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 220, Message 6 of 10 In article , the Moderator noted: > [Moderator's Note: On my US Robotics Courier 2400 modem, you use '!' > to force the modem to flash the hook. But on outgoing calls, why > wouldn't you just insert *70 on the front of the dialing string > instead, as in ATDT *70-123-4567? If you want to flash the hook after > the modem is already on the line, I guess you would get the modem's > attention, with three plusses or whatever, followed by ATDT !*70 O, > where the final letter 'O' means for the modem to go back on line. PAT] The "!" dial modifier also works with Hayes modems. You're right about prepending "*70," to the phone number, rather than trying to do it after the call is established. In fact, you CAN'T do it after the call is established, for two reasons: first, Hayes modems will give you an ERROR result code if you try to do an "A" or "D" command when you're already connected; second, if you DID hook-flash, you'd split the connection, which the other modem would see as a carrier loss which would cause it to hang up. The question has come up previously as to how to disable call waiting on INCOMING modem calls. I may have mentioned this here before, but it can be done fairly simply. You can't use Auto Answer (S0 > 0); your software must look for RING messages (or the RI lead to go high). Rather than issuing just an "ATA" command string to answer, use the string "ATH1D,!,*70,!;A". You might want to set S8=1, so the commas only cause a one second delay instead of the default of two seconds. Toby Nixon, Principal Engineer | Voice +1-404-840-9200 Telex 151243420 Hayes Microcomputer Products Inc. | Fax +1-404-447-0178 CIS 70271,404 P.O. Box 105203 | UUCP uunet!hayes!tnixon AT&T !tnixon Atlanta, Georgia 30348 USA | Internet hayes!tnixon@uunet.uu.net