Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!decwrl!ucbvax!unisoft!hoptoad!hsfmsh!daemon From: tnixon@hsfmsh.UUCP (Toby Nixon) Newsgroups: comp.dcom.modems Subject: Re: Setting High Speed w/ 'AT' command set Message-ID: <3825@hsfmsh.UUCP> Date: 13 Aug 90 15:55:34 GMT Sender: daemon@hsfmsh.UUCP Organization: Hayes Microcomputer Products, Inc. Norcross, Georgia Lines: 50 In article <9110@jpl-devvax.JPL.NASA.GOV>, Randy Parlier (parlier@puente.jpl.nasa.gov) writes: - The manual mentions that I can configure the modem to select - various operation speeds by entering an AT set command. The - only one it mentions is "ATBn" where - n=1 selects Bell 212A in the 1200BPS mode - n=0 selects CCITT V.22 in the 1200BPS mode. - - It does not mention anywhere on how to select 2400BPS mode. - - Can someone please help??? How do I select 2400BPS? Current Hayes modems have a register that allows you to specifically set the maximum connection speed. However,the modem you havee probably doesn't have this, but instead uses the "last AT speed" (the speed at which the last AT command was issued) to determine the maximum speed. When you dial a call, the speed at which you issued the "ATD" command determines the maximum speed at which the modem will connect; e.g., even on a 2400bps modem, if you ATD at 1200, the modem will not connect at higher than 1200. When you're answering, this is a bit more of a problem, especially if you're AUTO ANSWERING. If you receive a call after having reset the modem, how does it determine the "last AT speed", since you haven't given it a command? In Hayes modems, this is determined by the speed at which you issued the last "&W" command to write parameters to non-volatile memory. I would bet that when you did the "ATS0=0&W0" that you were set to 1200bps, so the modem "remembered" 1200bps as you "default" speed -- it recalls this speed as the "last AT speed" every time you power on the modem or reset it. You need to update this "stored AT speed" in the modem's non-volatile memory by simply doing an "AT&W" command at 2400bps. -- Toby P.S. All of this assumes that your modem works like real Hayes modems in these respects. If it doesn't, well, you'll have to contact the manufacturer. ----------------------------------------------------------------------------- Toby Nixon, Principal Engineer Fax: +1-404-441-1213 Telex: 6502670805 Hayes Microcomputer Products Inc. Voice: +1-404-449-8791 CIS: 70271,404 Norcross, Georgia, USA BBS: +1-404-446-6336 MCI: TNIXON Telemail: T.NIXON/HAYES AT&T: !tnixon UUCP: ...!uunet!hayes!tnixon Internet: hayes!tnixon@uunet.uu.net MHS: C=US / AD=ATTMAIL / PN=TOBY_L_NIXON / DD=TNIXON -----------------------------------------------------------------------------