302 security failures

On Apr 5, 10:05*pm, ContestID67 wrote:
Just to put in my $0.02 I have *NEVER* had a single issue with my
302. *Never. *Period. *About 6 years old now and all I have ever done
is send it somewhere for a re-calibration/certification. *And I have
never dumped the memory (but certainly have wrapped the memory).
Maybe I am just lucky.

All those that have never had a problem with their 302, please raise
their hands. *;-)

- John DeRosa

I had a 302A that had a failure, sent it back to R-Track after which
it failed again. Sent it back to R-Track for the memory and USB
connection upgrade and it failed again soon after.
Got a 302DDV and not had the problem since......
Those guys at R-Track do a great service and I feel sorry for them
that they are having to deal with this problem to an otherwise great
instrument.

Bob 7U

On Apr 5, 9:02*am, T8 wrote:

Next time you go to the glider try to download the same log. If it
fails make another flight, then try to download that new log, and the
one that failed previously. If either fails please try a different
download utility. Let us know what happens please.

I think, from my own experience, it is possible for the security fail
to go away without anything being done to the 302.

I never clear my 302 and record all flights at 2 second interval.
Memory was probably cleared when sent in for calibration and service
but the last time that happened was 2005. I have experienced about
2 security fails in over 700 hours logged at 2 sec and I don't think
any in the last 185 hours.

Looking back at my notes, I had a suspicion that the security fail
problem was related to the download utility being used, and that using
a different utility didn't show the problem. That was based on a
postdownload review of saved flight logs and their securty as reported
by Cambridge Aero Explore Plus. I must have lost interest though,
since I didn't come to any firm conclusion about that.

Andy (GY)

Looking back at my notes, I had a suspicion that the security fail
problem was related to the download utility being used, and that using
a different utility didn't show the problem. *That was based on a
postdownload review of saved flight logs and their security as reported
by Cambridge Aero Explore Plus. *


I just checked those logs. It turns out they were different flights
on the day day. I took a relight. The log files are 5A9C3GP1.IGC and
5A9C3GP2.IGC. The first fails security check and the second passes
security check when validated with Aero Explorer Plus. There was about
35 minutes between the first landing and the second takeoff and I did
nothing to the 302. A log for a flight 7 days earlier also reports
good security.

I don't remember now if the download utility failed them both, or just
the first one, but I removed the 302 and took it in to Cambridge as I
was on business in Memphis soon after seeing the problem.

This supports the idea that the 302 will heal itself, but not the idea
that the downloader utility type had a role.

Andy (GY)

Has anyone tried sending their failed logs to R-Track? I would think
they might be able to pinpoint the glitch in the checksum calculation.
There's probably an errant byte somewhere, maybe due to the memory
wrap-around, maybe not.

On Apr 5, 6:55*pm, Greg Arnold wrote:
My 302 is wrapping memory on every flight, because I have not cleared
the memory in several years. *A number of months ago I got a security
fail, but since then have not had a problem.

No, it's overwriting on every flight. It wraps when it gets to the
end of the memory space and goes back to the beginning. When it
wraps, it appears that there's a 10% or so risk of a security failure
on that one flight log. Roughly speaking, you have about a 50/50
chance of seeing a security failure every 500 flight hours at a 4 sec.
rate.

I like my 302. I'm just getting ticked that this thing is still
effectively in beta and that no one is working on the software to make
it the *great* instrument it should be.

-Evan Ludeman / T8

On Apr 6, 9:02*am, T8 wrote:

I like my 302. *I'm just getting ticked that this thing is still
effectively in beta and that no one is working on the software to make
it the *great* instrument it should be.

Not really surprising since everyone involved with the development has
moved on to new pastures.

It will be interesting to see how similar the new NK vario will be to
the 302 as the team seems to have come together again there.

Cambridge started to fall apart soon after I bought my 302. I am
pleasantly surprised that I can still get it repaired if fails, but
have no hope at all that there will ever be any design updates.

Andy (GY)

On Apr 6, 12:21*pm, Andy wrote:
On Apr 6, 9:02*am, T8 wrote:

I like my 302. *I'm just getting ticked that this thing is still
effectively in beta and that no one is working on the software to make
it the *great* instrument it should be.

Not really surprising since everyone involved with the development has
moved on to new pastures.

It will be interesting to see how similar the new NK vario will be to
the 302 as the team seems to have come together again there.

Cambridge started to fall apart soon after I bought my 302. *I am
pleasantly surprised that I can still get it repaired if fails, but
have no hope at all that there will ever be any design updates.

Andy (GY)

The next question is how long they are going to be in business after
NK starts selling their variometer at a lower price.

On Apr 5, 8:22*am, JS wrote:
You're right, it's about 100 hours.
* It's just another thing to deal with at Annual time. For many people
using "clear log" at Annual is sufficient to keep the gremlins away.
But if you fly a lot, that isn't enough. Perhaps stick a post-it note
in the logbook to remind you of when the next "clear log" is due...
* SPOT batteries should get changed at each Annual too. I put 200
hours on the 2 Lithium AAs (version 1) with no problem, but doubt I'd
push it another year.
* At the bottom is a way to make and test a log without flying, to
check 302 security.
Jim

Clearing the flight log memory in a 302 or 302A
This may help reduce flight log security issues on future flights.
Important Note: This will erase all flight logs in memory!
1. * * *Connect the 302 or 302A to a PC using the RS-232 serial cable that
was supplied with the 302.
2. * * *Power the 302 or 302A with 12 volts and make sure the unit is
turned-on. *The GPS antenna does not need to be connected.
3. * * *Run a terminal emulator program on the PC. *A good one to use is
HyperTerminal. *It is included with most versions of Windows. *To
access it go to:
o * * * Start Menu / All Programs / Accessories / Communications /
HyperTerminal
4. * * *In the "New Connections" window enter "302" for the Connection Name
and then click the OK button.
5. * * *In the "Connect To" window, set the "Connect using" parameter to
match the desired communications port. *This is the port which the
RS-232 serial cable is connecting with. *It is usually COM1, COM2,
etc. and will vary from PC to PC. *Then click the OK button.
6. * * *In the "COMx Properties" window set the parameters as specified
below and then click the OK button:
o * * * Baud Rate: 4800
o * * * Data Bits: 8
o * * * Parity: None
o * * * Stop Bits: 1
o * * * Flow Control: None
7. * * *You should now see GPS data sentences appearing in the
HyperTerminal window.
8. * * *Hold the "Ctrl" button on your computer's keyboard and hit the "c"
button (Ctrl-c). *The flow of GPS data should stop.
9. * * *At the "cmd" prompt type: "clear log" and hit the Enter key. *I
don't think there is any acknowledgement from the 302 other than that
the "cmd" prompt reappears.

Checking the 302 logger with HyperTerminal:

* Connect as above
Ctrl C
Type START
Allow it to log 10 minutes.
Type STOP
* Then download the log with the CAI 302 utility and check security.

BTW if you have SeeYou Mobile on a PDA connected to your 302 is also
easy to clear the log memory using the SeeYou Mobile built in terminal
emulator. You just need to know that entering "hex(3)" sends the
Control-C character to break into command mode.

A while ago I had posted instructions on how to do this on my blog...

http://www.darryl-ramm.com/2008/09/c...seeyou-mobile/

Darryl