The next window sets the COM port settings. The settings used for the Comet should be as follows:
Bits per second: | 115200 |
Data bits: | 8 |
Parity: | None |
Stop bits: | 1 |
Flow Control: | Hardware |
Click “ OK” when finished. After you have done this, save your new connection by selecting “ Save” from the “ File” menu and click “ OK.” A new connection icon will be added to your Hyper Terminal folder.
You are now ready to start entering AT commands.
In the terminal window, type:
AT<Enter>
Comet responds
OK
This confirms that the modem and your computer are communicating correctly.
To test the telephone line connection issue the manual answer command.
Type:
ATA<Enter>
The Comet will pick up the phone line, and try to communicate. Normally, this command is only used to answer an incoming call made from another modem. Thus the high pitched noise you will hear from the speaker. To abort the operation, press any key, or select “ Disconnect” from the “ Call” menu.
Dialing and Answering Techniques
Depending on what communications software you use to make modem connections, you may not have as much control of how the modem dials the telephone number. This section shows some useful examples of the AT commands used for dialing and answering operations. The command characters specific to each function are shown in bold type.
Dialing using the ATD Command
Touch Tone Dialing: | ATDT 555 1212 |
Pulse Dialing: | ATDP 555 1212 |
Tone and Pulse Dialing: | ATDP 555 1212 WT 24 |
14 Basic Modem Operation
