Garmin nuvi 3597 Trip Log Behavior

AFAIK, the 3597 records all trip logs. Have you looked at archived trip log files contained in \GPX\Archive?

With the amount I drive, I have ~10 days of travel stored in current GPX. All data in \GPX\Archive is older than the data in current GPX. The "missing" segments are however displayed with the "Where I've Been" tool. Sort of indicates the "real" trip log is stored in memory that is not accessible to the user and is transferred to current GPX and the Archive when the GPS is connected to a computer.
Next time you are using your GPS, try routing for only the middle portion of the trip to see if you lose parts of the trip log.
Mark

Current.gpx is just a copy of what is stored in protected memory and is not used for navigation or operation. Its purpose is for passing data to external programs like BaseCamp. Current.GPX is recreated from internal memory every time you boot your device, and of course is updated "on the fly" as you navigate or update waypoints and routes.

I am not sure what is going on with your 3597 as I have not experienced that problem, although I don't monitor the trip log as carefully as you do. I do use routing frequently though, and from what I can remember all my recent travels are showing. I wonder if these missing segments will show up when this date range rolls over to the archive. Have you tried importing to BaseCamp (called tracks in Basecamp) to see what shows up?

I'm not sure if Current.GPX is updated "on the fly". Granted that an nuvi 855 may operate differently than a nuvi 3597. I have had the nuvi 855 connect to the PC in an abnormal way. Would never have to type in the unit's password when connecting (normally I would have to type it in). When the nuvi 855 connected in this abnormal way, the current.GPX was identical to the current.GPX I downloaded a week earlier. Reconnecting fixed the problem, updating the current.GPX to the current weeks data. I'm not aware of any diagnostic on the nuvi 3597 that allows viewing current.GPX while navigating to verify updating "on the fly".

Tracks with missing segments can be found in the GPX\Archive folder and verified to be missing in Basecamp , so they seem to be gone for good. I checked the GPS archive back 4 months (when I purchased the nuvi 3597) and found missing segments. This would be with firmware version 4.70 so I can safely say that the problem has persisted ever since I purchased it. Will change from MS to MTP to see if that makes a difference.
Mark

As I think about this, you are right. It isn't current.gpx that is updated on the fly ... it is the protected memory that is updated, which will be reflected in current.gpx the next time you reboot ... sorry for the misleading info.

That said, I have still not noticed any missing segments on the tracks I have looked at, but will start paying more attention.

I admit it can be subtle. If you always route from start to finish, it's not very noticeable that the track ends at the road and not your parking spot. Once I suspected something was amiss, I tested for a week. My procedure was to turn on GPS several blocks from home/work. Drive another four or five blocks and command the nuvi 3597 to navigate to work. Parking is about block from the "work destination" stored in the nuvi. Leaving work, a similar process is followed. Drive a few blocks then turn the nuvi on, wait a few more blocks to "route"
to home. When I get home I drive around the block before pulling in to the drive. Going to work, I get two "track segments", one track segment for the first several blocks and one track segment for the routed portion of the trip. No track segment for driving into the parking lot. On the return trip I only get the trip segment while I'm routing. The key to observing the feature is to drive a few blocks with the GPS before routing is started and a few blocks after routing has completed.
Mark

It seems to me that my devices act differently when they are attached to my computer depending on whether or not they are on or off at the point of attachment.

If off - and I attach to the computer - both the 765 and 2595 seem to go into what I will call "boot mode". I infer this because I see the "copyright" and/or "loading maps" messages before I see the symbols indicating that the device is attaching itself to my computer.

If on - and I attach to the computer - the devices immediately display the symbols indicating that the device is attaching itself to my computer.

Now I mention this because I want to distinguish between a boot sequence and this attachment-while-on sequence. If - while on - I "save" a new favorite (say be picking a recently found point and saving it) and then attach the device to the computer and look at the "current.gpx" file with EPE, I find that the point I just saved is included.

This implies to me that "current.gpx" is updated "on-the-fly"

What are your thoughts on this?

That is a good observation John, but I don't know that it proves that current.gpx is continuously updated. It is possible that it is the transition to mass storage mode instead of (or in addition to) a reboot that causes the nuvi to dump its internal memory to current.GPX. Since there is no way to observe the files while it is operating in navigation mode, there is really no way to know unless you can get an authoritative answer from a Garmin engineer.

My guess (and it is only a guess) is that current.gpx is not updated "on the fly" as you operate in navigation mode. In any case, it would seem that current.gpx should be up to date any time you can look at its contents.

I have concluded that the device "writes" "current.gpx" when it attaches to the computer - as I can see this from the "timestamp". So, we cannot know, as you stated, whether the device does anything on the fly.

When you speak of CURRENT.GPX are you only considering the copy which is visible to a computer or are you considering the actual hidden file?

The hidden file is updated on the fly as points are entered. The visible copy is only updated when the unit would be connected to a computer. You can test this by creating a route and then adding an intermediate point. The intermediate point can then be seen in SAVED places which we know is part of CURRENT.

"If a tree falls in a forest and no one is around to hear it, does it make a sound?"
Mark