M84 datalogger

Discussion and support for MoTeC's previous generation of entry level ECUs

M84 datalogger

Postby dr350 on Tue Jun 22, 2021 9:24 am

Hi

We are working on a vehicle that has a motec m84 installed, and when looking at the data we see strange maximum values ​​in several channels, for example: TPS: 6554, rpm 65535, error group, lambda, etc. This occurs when the motor stops, or the current is cut off.

Any problem in the wiring or installation?
Setup?

Thanks, Regards!
dr350
 
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Re: M84 datalogger

Postby David Ferguson on Wed Jun 23, 2021 2:43 am

When you say "looking at the data", is this an M84 logged data file, or from some device (dash/logger) that is communicating with the M84?

If it's from another device, you might want to make sure the M84 and that device are always a powered at the same time to the communication will always work.

For example, I like the dash and ECU to be powered with the master switch in dedicated race cars. The Ignition switch just controls power to the injectors and coils. This allows cranking the engine without ignition to register oil pressure prior to enabling the engine to run with the ignition switch.
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Re: M84 datalogger

Postby dr350 on Wed Jun 23, 2021 3:25 am

Hi,

Sorry for not being more specific.
It is in the logger data m84 file.
I attached screenshot on i2.

Thanks,Regards!


David Ferguson wrote:When you say "looking at the data", is this an M84 logged data file, or from some device (dash/logger) that is communicating with the M84?

If it's from another device, you might want to make sure the M84 and that device are always a powered at the same time to the communication will always work.

For example, I like the dash and ECU to be powered with the master switch in dedicated race cars. The Ignition switch just controls power to the injectors and coils. This allows cranking the engine without ignition to register oil pressure prior to enabling the engine to run with the ignition switch.
Attachments
Untitled.png
i2 capture
Untitled.png (130.88 KiB) Viewed 1637 times
dr350
 
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Re: M84 datalogger

Postby David Ferguson on Wed Jun 23, 2021 4:04 am

If I had that log file, I would zoom in to the peaks and try to understand why they occur.

I would tend to ignore them (I would zoom in and scroll the data to running data only, then the min/max would be valid value).

To prevent them from going in the logging file at all...
What are your logging conditions (Adjust->Data Logging Setup->Start/Stop Parameters. I tend to start when the engine is either cranking or running (RPM > 250 for 0.1 sec), that can eliminate incorrect data samples.
David Ferguson
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Re: M84 datalogger

Postby dr350 on Wed Jun 23, 2021 5:42 am

Ok, I see if I can find something the moment where the peaks are.

Yes, we have been working that way, leaving the peaks on one side or the other.

I had done tests with the data logging setup start / stop but it continues.
(ex: start: RPM> 200,300,500-- stop<500,300,100, 2 a 5s.)

Thanks, Regards!



David Ferguson wrote:If I had that log file, I would zoom in to the peaks and try to understand why they occur.

I would tend to ignore them (I would zoom in and scroll the data to running data only, then the min/max would be valid value).

To prevent them from going in the logging file at all...
What are your logging conditions (Adjust->Data Logging Setup->Start/Stop Parameters. I tend to start when the engine is either cranking or running (RPM > 250 for 0.1 sec), that can eliminate incorrect data samples.
dr350
 
Posts: 25
Joined: Sat Nov 23, 2013 4:35 am

Re: M84 datalogger

Postby SDean on Wed Jun 23, 2021 8:46 am

Hi,

This occurs when the ECU hardware resets whilst the logging is running, the maximum value for the channels is reported and logged during the reset process, this will also occur if the ECU is power cycled whilst the logging is running.
Stephen Dean
MoTeC Research Centre Melbourne, Australia
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Re: M84 datalogger

Postby dr350 on Fri Jun 25, 2021 12:25 am

Hi,

I really appreciate this learning !!!

Thanks You All, Regards!!



SDean wrote:Hi,

This occurs when the ECU hardware resets whilst the logging is running, the maximum value for the channels is reported and logged during the reset process, this will also occur if the ECU is power cycled whilst the logging is running.
dr350
 
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