INTRO
2
Intro / Getting Started
Now that you have your new Kantronics unit connected to your radio and computer, let's take a
moment to see what it is and how to make it understand what you want to do. A Terminal Node
Controller (TNC) is very similar to a telephone modem because it receives digital signals from the
computer (Terminal) and converts them to tones suitable for transmission to distant location. The
TNC also receives tones from your radio and converts them into the digital signals understood by
your computer. A TNC, however, does much more, because it controls the push-to-talk line of your
transmitter, keying the radio whenever it needs to send data. It also converts the data into a
"packet", adding the required addressing, error checking and control information to insure the data
gets from one Node to the next. The error checking implemented in your TNC must be the same
as the error checking used by any other station you want to talk to and this standard method is
called a protocol. The protocol used in Amateur Radio Packet TNCs is called AX.25. Different proto-
cols are used for other modes of operation, such as AMTOR.
In order for your TNC to do something, you must issue instructions to it, letting it know exactly
what you want done. In order to accomplish this, the TNC must be in the Command Mode (expect-
ing you to give it instructions) and any time you want to change the way your TNC operates, you
must be in this mode. The TNC tells you that it ready for your commands by sending you the
prompt
cmd:
.
When you first turn on your TNC out of the box (or after a hard reset) you may see some garbage
characters on your screen. The TNC is performing an autobaud routine. It is sending the same
massage over and over again at different baud rates. When the TNC baud rate matches the baud
rate set in your terminal (communications) program, the display will read:
PRESS (*) TO SET BAUD RATE
When these words are readable press the asterisk,
*
, on your keyboard. This will set the baud rate
until the TNC is turned off; keep reading for how to avoid having to do this all the time. Then the
TNC will display the following:
ENTER YOUR CALLSIGN =>
At this point enter your amateur callsign. This callsign will be used by the TNC for many different
things, including being in every packet you send and deciding if a packet it receives is specifically
for you. Now you should see the sign-on message and command prompt on your screen, as:
KANTRONICS sign-on-message
cmd:
In some cases (notably Commodore-64 users with the Kanterm program and some dumb termi-
nals) the
cmd:
prompt may not appear. This is due to the TNC sending lower case characters and
the terminal doesn't recognize them. In these cases, you will probably see only the colon (
:
). This
can usually be resolved by turning the LCOK command OFF.
The
cmd:
prompt means the TNC is ready to listen to you. Anything you type will be be inter-
preted as a command. If the TNC doesn't understand, it will display:
EH?
To change a command setting you type the command, a space, the argument (a number or what-
ever is appropriate) and then the RETURN or ENTER [
↵
] key. If you turn the TNC off and back on
