The AT command set was originally made popular by Hayes Microcomputer. Similiar to the way microsoft dominates software today, Hayes once dominated the consumer modem industry and their syntax of sending commands to a modem dominates to this day. The AT command set is detailed in most comprehensive modem manuals. Some examples are ATH0 to put the modem on-hook, ATZ for reset, and ATL3 to make the speaker as loud as possible (more useful is ATL0 to shut it up). I am unaware of any numbers blocking capabilities built into the original command set. If you want to check it out, unplug your modem from the line and send it the command ATX1DT911 and see if it dials. The X1 portion tells it to ignore dial tone so it will blind dial without a line connection. Listen for the three DTMF tones to see if call blocking is implemented.
Jon D. Curtis, P.E. Curtis-Straus LLC phone: (508) 486-8880 527 Great Road fax: (508) 486-8828 Littleton, MA 01460 email: [email protected] USA
