- Does the tnc-x have some sort of watchdog that can cause a restart from time to time? I ask because four times in the last 72 hours I have found our recentMessage 1 of 2 , Aug 7, 2008View SourceDoes the tnc-x have some sort of watchdog that can cause a restart
from time to time? I ask because four times in the last 72 hours I
have found our recent digipeater/igate install of javaprssrvr not
communicating with our tnc-x via the USB port. We are using the USB
interface to the FTDI chip, and we are also powering the tnc-x via
the USB port. This is the only USB tty type device installed on the
computer running javaprssrvr under Centos, hence, at boot it is
udev'ed to ttyUSB0. When communications have failed, I have found a
second device ttyUSB1 listed in addition to ttyUSB0 even though
communications were initially establised on ttyUSB0.
At this point, I can restore communications to the tnc-x in two ways.
First, I can simply reboot the computer which transiently powers off
the tnc-x, and everything comes back up with javaprssrvr and the tnc-
x both connected to ttyUSB0. The other way I can restore the hung
system is to change the javaprssrvr config file telling it to look
for a serial connection on ttyUSB1, restart javaprssrvr, and
everything goes back to working.
This suggests to me that the tnc-x is dropping the connection from
its side on ttyUSB0 and asking Centos to reconnect which it does, but
on ttyUSB1 since ttyUSB0 has not yet timed out. Is this possible?
Ideas? Thanks in advance!
73 -- John
- ... Our tnc-x intermittent communication problem may be resolved, and I want to remove any lingering concern about the tnc-x per se. We had the tnc-x at aMessage 2 of 2 , Aug 29, 2008View Source
> from time to time? I ask because four times in the last 72 hours IOur tnc-x intermittent communication problem may be resolved, and I
> have found our recent digipeater/igate install of javaprssrvr not
> communicating with our tnc-x via the USB port. We are using the USB
want to remove any lingering concern about the tnc-x per se. We had
the tnc-x at a remote site dropping the connection to the USB port at
least once every 24 hours. We retrieved the tnc-x, and I duplicated
the software (javaprssrvr running on Centos) at home and confirmed the
While moving the tnc-x around, I noticed the power on LED would blink.
Just tapping the tnc-x caused the power LED to blink. Studying my
soldering, I found R15 unsoldered on both legs (it's near the board
edge). Without looking at the schematic, I thought I had the problem
fixed, but the tnc-x continued to intermittenly drop the USB
connection. Then I looked at R15 in the schematic and learned it is
merely the ballast resistor for the power LED, and I shouldn't have
expected solding it to fix anything, but the experience did cause me
to recheck all other solder points. I found an IC socket pin
unsoldered too (getting old is the pits). Honestly, I don't remember
which pin on which IC, but I soldered it and went over every other
solder joint with reheat and reflow. I also removed and resocketed
The tnc-x has now run over eight days without failing, and this
weekend we will return it to the remote site.
73 -- John