USB logger data dropouts | AEM
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kb58
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USB logger data dropouts

What could be causing data dropouts while logging via USB? I have some logs where it happens every few seconds. The USB is plugged directly into the ECU, not via a cable. Because the engine keeps running fine, it's not real, so it doesn't seem like it's EMI. Has anyone else see this? 

 

AEM_BB
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What USB stick are you using,

What USB stick are you using, how many channels are you logging and at what rate? This typically happens when the USB stick can't keep up with the write speed of the ECU. It may help to format the USB stick in RAW (USB Logging -> Get Logs, then right-click in log list and select Format Drive). Based on the filename it looks like the stick hasn't been formatted for a while; it's using a file number format from much older firmware.

kb58
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This one: http://www.frys.com

This one: http://www.frys.com/product/7417985?site=sr:SEARCH:MAIN_RSLT_PG

No specs on speed, but what speed do I need? As far as how many variables were being logged... not sitting in front of my laptop at the moment, but probably about 50-60 at 50Hz.

The drive isn't that old, purchased in April or May 2015, though I don't remember formatting it. Does that still have to be done these days, because it appeared to work as-is.

AEM_BB
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By default, USB drives are

By default, USB drives are almost always in "FAT" format which is Windows compatible. This will work with Infinity, but formatting the drive using Infinity Tuner sofware will put it in a "RAW" format which allows faster speeds and should be more consistent. Also, if for any reason power is completely cut off to the ECU (e.g. if the master switch is hit on a race car) you will lose the log in FAT format, but the log will be saved in RAW format. The disadvantage is that logs must be downloaded through Infinity Tuner as opposed to removing the drive and plugging it directly into your laptop.

kb58
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To close this out, I formated

To close this out, I formatted the 16GB thumb drive and now it works perfectly. The only surprise was how it instantly formatted the drive, no progress bar, no counting up % display, just... boom. I'm curious what's going on that it takes zero time to format 16 thousand million bytes!

kb58
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Nuts... How how do I format

Nuts... How how do I format the drive again, in "raw" format? You noted that it's through Tuner but I can't find the screen again. Thanks.

AEM_SB
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To format the USB flash drive

To format the USB flash drive:

With the USB flash drive connected  to the ECU, go to Logging >> USB Logging - Get Logs.  In the new window that opens, right-click the list of files and select 'Format Drive'. 

 

The format process happens quickly because the ECU does not manually overwrite all the old files with 'zero' or delete each one individually as you might assume. Somewhere on the drive is a special memory location that stores which parts of the flash drive contain valid data files and which parts of the flash drive are safe to use for new files; the list of 'valid data files' is changed so that all parts of the flash drive are now considered safe to use for new files.

Hope that helps,

SB

Turbonutter
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Having read the above posts,

Having read the above posts, I formatted my memory stick using the tuner software, so it is now in raw format. I was suprised that the log files are now about ten times the size they were before, so take forever to save - Is this correct?? If it is I will go back to FAT format, as somtimes i need to quickly download logs..