Chip,

What was the failure mode that you had?

It seems like you're almost asking for complete duplication of all your
systems, GPS, logger, and power, plus complete matrix switching across the
"network".

You need a switch upstream of your loggers that toggles between the data
streams between the two GPS data sources. You could configure it as a three
position switch:
1) GPS1 to LOG1 and GPS2 to LOG2
2) GPS1 to LOG1 and LOG2
3) GPS2 to LOG1 and LOG2

You could also use a NMEA sniffer that alarms a lost data stream so you can
make the switch (there is some allowance for loss of NMEA data stream, I
think).

For power, here's what I did. I run all the systems off my main battery. I
also have a smaller battery dedicated to the GPS source and data logger. If my
main battery fails, I switch to the backup. At least I get my data logged.

If you do a FMEA (Failure Modes and Effects Analysis), I bet you'll conclude
that the highest probability of failure is with the power system. Maybe you
just need some psycho therapy to get over your one failed relationship? ;-)



Jim Vincent
CFIG
N483SZ
illspam