treesh@bach.helios.nd.edu (09/22/90)
In reguards to a question asked about the modem swith the effects DTR controll the is not much of an effect that you will see when using most termial programs since most terminal software does not really need DTR controll, it will work with or without in in most cases. DTR is part of the RS232C standard, and is used as a signal to the modem to tell the modem that the computer is ready to do I/O with the modem. Most modems now-a-days have switch settings, or non-violite configurations to program how the modem will react to a DTR signal. The traditional controll is "FORCE DTR ACTIVE". This will usualy make one of the LEDS on your modem come on called TR. If that light is on, then the modem is now ready to communicatate with the computer. For the most part, when you power up your comm~rodore computer, the DTR signal is sent to the modem, thus your modem will 'work for you'. If you have one of those strange interfaces that wont give DTR to the modem at power up, or inverts the signal, then you may find that your modem wont do the follwing: Wont dail. Wont autoanswer. Wont connect. Wont take any commands. If this is the case, then Forcing DTR active is best for you, this will make the modem work alaways, no mater what kind of stupid interface ya have! The newer modems can be programed to do other intresting things with the DTR signal. The most commom setting for fany software is this: AT&D1 - Tells the modem to HANGUP immideaditly upon the loss of the DTR signal. In this configuration, a BBS program or TERM program can quickly change the DTR signal, and force any very fast dissconnect.