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VIDEO4Technical / DetectingWhyAVIDEO4UnexpectedStoppedRecording

Detecting why a VIDEO4 unexpected stopped recording


There is nothing more frustrating than getting back to the pits to find that you’ve either got a partial set of data. This page is intended to help you identify why the VIDEO4 stopped logging at a particular time. The reasons are given in the approximate order or likelihood based on our experience supporting the VIDEO4 since it was launched.

Power supply problems (or over temperature)

Check the files in the directory and look at the names of the files. The last file that gets updated in the directory is the IDX file – if there was not time for the VIDEO to properly complete the file then it will have the extension “ID~”. This normally indicates that either:

  • the VIDEO4’s power supply was unexpected lost, or the voltage dropped below 9v. Note that the loss of power needs only to be very brief to cause a problem.
  • the VIDEO4 got too hot and shutdown to protect the components, this happens when the unit gets to abut 70 degrees C. When the unit goes over temperature, power is removed from the main board and so the symptoms are the same as for a shutdown due to loss of power.

Of these the loss of a good power supply is by far the most common problem, and it can be triggered by either the voltage going to low due to a poor battery/charging system or a momentary loss of power due to a bad connection in the power supply. If problems persist then it’s often convenient to try running the VIDEO4 directly from it’s own battery with a direct connection.

Note that if the power supply is lost, the VIDEO4 should automatically start up as soon as the power is available again. This is done with the “RESTART.CMD” file:

  • When the VIDEO4 starts recording for any reason (manual, autostart, remote start) then the file “RESTART.CMD” is immediately written to the root directory of the compact flash card.
  • When the VIDEO4 stops logging in a controlled way then this file is deleted.
  • If the VIDEO4 starts up and sees this file on the card then it immediately starts recording

This means that if the VIDEO4 didn’t stop recording “properly”, for example due to over temperature or loss of power, then as soon as it restarts it will see this file and resume recording. So if you see this RESTART.CMD file on the compact flash card it is another sign that the recording was not correctly terminated.

Card full

If the card is full and loop mode is not enabled then the VIDEO4 will simply stop recording. If the recording has terminated due to a full card then the power light will be blinking twice.

Autostart/stop enabled

Since the VGL file can be used to set up autostop conditions, then this is a possible source of error. Check that the autostop conditions have been set correctly, or if in any doubt at all remove the autostop condition.

Failed card

This is surprisingly common failure mode in motorsport where the cards are getting “a hard life” with large temperature extremes and high levels of vibration etc - compact flash cards have to be considered as a “consumable”. It’s a very different application to a typical digital camera! Sandisk cards tend to be the most reliable, however be aware that most of these cards available on the internet are counterfeit. For this reason we strongly recommend buying them from a large and reputable retailer. If the VIDEO4 seems to behaving erratically, then trying a brand new, good quality memory card is a good place to start.

Incorrect system configuration

It is possible for the VIDEO4 to stop logging if it is incorrectly configured, please check the pages on “connecting systems”. The most important thing here is that if there is no DASH in the system then the VIDEO4 should be set to not output any data. If set up incorrectly then the data bus can get overloaded, generating 1000’s or errors and eventually sees the correct sequence to cause it to “stop logging”

Vibration

Although the VIDEO4 is solid state and therefore largely immune to vibration, there are limit above which it will not work. The limiting factor is the contact between the flash card and the VIDEO4. At high levels of vibration the card will momentarily lose contact with the pins on the VIDEO4, or in extreme cases the memory can can get ejected from the unit.

Card too slow

If the card is an older type, or the bit rate has been set very high it is possible to get recording to stop as the VIDEO4 cannot get the data onto it quickly enough. In most cases this will not occour as the VIDEO4 will automatically reduce the data rate, so although the video quality will be reduced, the recording will continue. This normally happens when there are internal errors on the memory card, which can completely block writes to it for several seconds. If the card is too slow then it’s best to simply replace it for a better card – generally we recommend a genuine Sandisk card, or buy a card from us that we’ve tested at the maximum data rate. Note that most memory cards do have a speed rating printed on them, eg “10x” “40x” “100x” however this is more to do with marketing than actual performance, so buying a card with a particular speed rating is not an absolute guarantee it is fast enough, although it might be taken as an “indication” of performance. If recording does fail due to a slow memory card then the recordings will be completed correctly, and the power light will be blinking 3 times.

The VIDEO4s firmware crashed

Before we release any new VIDEO4 firmware we test it recording with all options enabled, recording at the maximum bit rate in loop mode recording for several days continuously. We then follow this up with road and track testing – but it’s always possible that there are “bugs” in the firmware. If the recording fails due to a bug then the “internal” directory will contain a special file “RTCGXXX.TXT”, email this file to Race Technology and we can check the source. Note that since the VIDEO4 was launched we’ve not had a single confirmed report of a failed recording due to firmware – so while it’s possible, this is unlikely to be the cause.

General diagnosis

If the VIDEO4 is able to correctly complete the files before recording was terminated, then load the run file into the analysis program and check in the run manager. This will normally give the reason why the recording was terminated:

Page last modified on November 19, 2013, at 11:26 AM