Coordinating Pacterm and Your TNC
Several TNC parameter values affect how Pacterm communicates with the TNC.
Coordinating BAUD Rates: The Autobaud Routine
The first time your TNC is used, it runs an AUTOBAUD routine to assure that
the TNC baud rate is the same as that of Pacterm (or whatever communication
software is in use at the time).
The TNC’s AUTOBAUD routine works as follows:
1. AUTOBAUD sends and resends the message “PRESS (*) TO SET BAUD
RATE” to Pacterm, at one baud rate after another. When the TNC’s baud rate
matches that of Pacterm, you can read this message in a window on your
screen; if the two rates do not match, the message appears garbled.
2. Any time while this message is being sent, whether it is readable or garbled
on your screen, enter the “*” character (SHIFT+8 key combination).
3. When the AUTOBAUD routine receives, the “*” character from the serial
port, it uses that character to determine Pacterm’s BAUD rate.
+ NOTE: Do NOT use the “*” key on the number pad.
4. AUTOBAUD then sets the TNC’s BAUD rate to match Pacterm’s BAUD
rate. The TNC’s BAUD rate will be set to 9600 (Pacterm’s default BAUD
rate) unless Pacterm’s BAUD rate was changed before running
AUTOBAUD.
Technical note: The TNC’s BAUD rate is stored in the TNC as the value of the
ABAUD parameter, so when you use the TNC later, it will start with that BAUD
rate. This is made possible by an internal lithium battery supplied with the
TNC. Later, you can change the TNC BAUD rate if you want, as long as you
change Pacterm’s BAUD rate to match the new TNC BAUD rate.
Pacterm v 2.0 Coordinating Pacterm and Your TNC
User’s Guide 76 KAM’98 v 8.3