IN CASE OF DIFFICULTY
22
In Case of Difficulty
Kantronics TNCs are manufactured to very stringent quality standards. If you have followed the in-
stallation procedures outlined in this manual, it is highly unlikely that you will encounter a failure.
If you do have difficulty, use the procedures described in this section to assist in isolating and cor-
recting the problem.
TNC Does Not "Sign-On" to Computer
1. Carefully recheck cabling between your computer serial port and the TNC.
2. Check carefully to insure the Transmit Data, Receive Data and Ground leads are connected to
the proper pins.
3. If you have made a 5 wire connection to the computer serial port, change to a 3 wire connec-
tion.
4. Check your terminal program to be certain it is booted with the correct communications param-
eters (serial port, baud rate, parity).
5. Check to insure that the RS-232/TTL jumper is properly positioned for your computer.
6. Try a "Hard Reset" using the Test/Normal jumper. (Operate your terminal program at 300 baud
when performing a hard reset.)
You Are Unable to Make a "Connect"
1. Issue a connect request and observe the XMIT LEDs. If an XMIT LED illuminates, check to in-
sure that the radio is connected to the corresponding radio port.
2. Observe the radio to determine if it is being switched to the "Transmit" condition. If not,
recheck wiring between the TNC radio port, PTT pin and ground on the microphone jack.
3. Turn the VHF radio squelch control to "OFF" and see if the RCV LED illuminates an the Packet
controller. If it does not light, recheck the audio connection between your transceiver and the
TNC.
4. If possible, monitor your transmitted signal with another radio. If the transmitter is keying to
"Transmit" but weak or no audio is monitored, increase AFSK output as necessary using the
AFSK Output jumper or resistor change. (SEE the AFSK Output Level section.)
Cannot Transmit on Any Port
1. Check the 8BITCONV command. Many dumb terminals, and some Commodore programs, will
not operate properly with this command turned ON. The symptoms most common for this
problem are, that everything seems to work fine in Command Mode, but upon entering Con-
verse Mode, the TNC no longer seems to operate at all. Usually you cannot return to Command
Mode with a Ctrl-C, pressing return does not send a packet and it just seems like the serial ca-
ble between your computer and TNC has been unplugged.
2. Check your PARITY setting in the computer and in the TNC. These must match or else the
computer may not really be sending the SENDPAC character ($0D) to the TNC.
Cannot Return to Command Mode
1. The single most common cause of this is, that the STOP character (and usually XOFF) have
been inadvertently set to the same as the COMMAND character. This is usually caused by the
use of the dollar sign ($) as a streamswitch. If you use the $, be aware that you cannot enter
hex values without PASSing the dollar sign. Symptoms for this usually are, that you can talk to
the TC fine in Command Mode, you can usually talk to others on the air, but you just can't get
back to Command Mode. (In non-packet modes, you will find that you cannot enter any of the
special Ctrl-C directives either!) With most PC terminal programs, pressing Ctrl-C will display
the heart character, but you still don't get the cmd: prompt.
To Next Page
Loading...
