MPVI2 VS MPVI1 Sampling Rate

Hey guys,

Has anyone who has upgraded compared the sampling rate between the MPVI1 and MPVI2?

The best way I know how is to open a log and export to CSV, opting NOT to interpolate data gaps. This will show you the actual samples reported back. From there, I open in excel, pick a channel, pick a start and end cell over at least a few seconds of time, and divide the number of samples in that time by the time elapsed.

If someone could even post logs from each interface on the same vehicle and channel layout, I could check on the sample rates.

Quote:

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Originally Posted by CCS86

Hey guys,

Has anyone who has upgraded compared the sampling rate between the MPVI1 and MPVI2?

The best way I know how is to open a log and export to CSV, opting NOT to interpolate data gaps. This will show you the actual samples reported back. From there, I open in excel, pick a channel, pick a start and end cell over at least a few seconds of time, and divide the number of samples in that time by the time elapsed.

If someone could even post logs from each interface on the same vehicle and channel layout, I could check on the sample rates.

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Here you go, just performed a log of a stock JGC using the MPVI1 and MPVI2 and included the channel layout.

MPVI2
Attachment 85552

MPVI1
Attachment 85553

Channels
Attachment 85551

Homer, I appreciate you taking the time to upload those files.

It looks like because of the relatively few number of channels you were logging, and the commanded sampling rates, there isn't a difference between the two.

Essentially all your channels were set to record at 5 or 10 Hz, and they all hit those values. You got about 63 Hz on the external wideband channel.

If you were inclined to retest, I modified your channels.xml to remove the interval. This should make them record as fast as possible. You could double check this after loading the channels file, by right-clicking a channel and looking under polling interval. It should say "fastest".

Unfortunately, I no longer have the MPVI 1 but I can re-run the log on the MPVI 2 if that helps.

I wouldn't sweat it. Without a direct comparison, it would be hard to draw a conclusion. Definitely try out the new channels list for your own purposes though. No sense in running a low sampling rate, when it can do so much more.

For comparison:

In your log (ignoring the external WB) you are getting about 243 samples / sec

On my MPVI1 (Ford Copperhead), I am logging 41 channels, at a total of 826 samples / sec

Most vehicle sample rates should be nearly identical, as the limiting factor is the vehicle, not the interfaces.

For the wide band A/D inputs, the MPVI2 should be far superior to that of the MPVI.

Quote:

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Originally Posted by Keith@HPTuners

Most vehicle sample rates should be nearly identical, as the limiting factor is the vehicle, not the interfaces.

For the wide band A/D inputs, the MPVI2 should be far superior to that of the MPVI.

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Keith, can you elaborate on that? I found a previous post where you were talking about the differences between sampling rates for the a/d inputs on the old pro cable in various versions of the software, and that due to not averaging, the faster sampling rate may not actually be as useful or accurate. https://forum.hptuners.com/showthrea...t-Sample-Rates

What changes have been made for the new pro link that are an improvement since it is still advertised as 100hz. Does it do an averaged or capacitor buffered of the in-between values?

The Pro Link samples at about 6400 Hz. We take an average of those samples, that's where the 100 Hz sampling rate comes from. This is quite a bit faster than the MPVI.

Also, the hardware we used for the analog input also allows us to sample at a faster rate, compared to the MPVI.

Quote:

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Originally Posted by MarkS@HPTuners

The Pro Link samples at about 6400 Hz. We take an average of those samples, that's where the 100 Hz sampling rate comes from. This is quite a bit faster than the MPVI.

Also, the hardware we used for the analog input also allows us to sample at a faster rate, compared to the MPVI.

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Mark, is there any way to get a software modification to be able to access that raw data without the averaging/interpolation. I would be extremely excited if I could actually get 6,400hz data into the scanner without collecting and processing that data separately with an oscilloscope and then scratching my head about how to synchronize it to the rest of the log data. That opens up all kinds of new possibilities as far as monitoring port pressures, etc as opposed to averaged data coming in just once per engine revolution at high speeds, which is of basically zero use for that type of analysis.

Quote:

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Originally Posted by ZephTheChef

Mark, is there any way to get a software modification to be able to access that raw data without the averaging/interpolation. I would be extremely excited if I could actually get 6,400hz data into the scanner without collecting and processing that data separately with an oscilloscope and then scratching my head about how to synchronize it to the rest of the log data. That opens up all kinds of new possibilities as far as monitoring port pressures, etc as opposed to averaged data coming in just once per engine revolution at high speeds, which is of basically zero use for that type of analysis.

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Hell yeah, I like the way you think!

When did that spec get updated?

When first released Pro Link was advertised as 10hz sampling rate with the old MPVIpro always being 100hz since 3.0 came to be.