Drivetrain New graphing software
#1
07-24-2010, 06:30 PM
New graphing software
Don’t know if this subject is allowed since I don’t see this co. as a vendor here but I’m trying out a new data logging device from Bytetronik. I don’t know if there’s any vendors here doing the same thing so thought I’d share the information. Pretty neat the way it gathers data and literally posts it to a database and then is downloaded to create a graph of the run. I just insert the little recording device into the OBD port and “record” a run. I then download it to my laptop and play back via the Bytetronik Dataviewer. It records 40+ bits of information 8 times per second to create the spreadsheet and graph. The graph can be manipulated to show different measured items that you may want to view. From what I understand, it will be able to store different “maps” that can be applied. Don’t know if that part of the software is active. I’ve put a couple of runs on my laptop and changed the graph around to show different values. Once I learn more about how all this works I’ll share some more.[/FONT]
#2
08-01-2010, 04:18 AM
#3
08-01-2010, 05:21 PM
#6
08-02-2010, 05:44 AM
Interesting writeup on how it all is recorded from Jay in their "Data Logging 101" section of mynesperformance.forumotion.com/technical-articles.
"The data logging rate or speed (samples per second) is dependent on what data is to be logged. When logging engine data, 99% of the data changes no faster than about 5 times per second (one state to another and back).
The engine state is ultimately controlled by the driver’s right foot. The fastest external muscle in the humans is the eye-lid muscle. It goes through one blink-cycle in about 100 milliseconds.
A mathematician named Harry Nyquist found out (in 1928), that for anything you want to record, you only need to record at twice the maximum frequency contained in the recorded signal. So, for the human eye-lid, the required minimum logging speed is 20 times/second. The human foot, controlling a gas pedal, is much slower. Remember, the frequency is not measured from idle to WOT, but from idle to WOT and back.
The second parameter determining the logging speed is the statistical nature of the combustion process itself. No two combustion events in an engine are identical. Therefore, to get meaningful data, multiple combustion events must be averaged to see the overall effects. If each combustion event is analyzed and recorded, meaningful tuning data can’t be seen in most cases. At 6000 RPM an engine goes through 50 engine cycles per second (a 4-stroke engine cycle requires two rotations per cycle). At a logging speed of 12.5 samples per second this would mean that the resulting data is the average of 4 engine cycles.
The above means that data logging engine data needs to be done at 10-15 samples per second. Anything more creates only more data points which do not contain any additional information, but are harder to analyze.
The ByteTronik Data logging Hardware using the Siemens BMW/MINI specific KWP2000 protocol at 9600 baud rate thru OBD II port and using ByteTronik Data logging patch software in the ECU. Samples engine data between 8 – 11.5 samples/second. Without the patch software, it will log only 1 -3 samples/second using the factory Siemens BMW.MINI protocol at 9600 baud rate thru OBD II port.
When evaluating data-logging products be very aware of the difference between channel rate and sample rate. Many manufacturers specify the channel rate, but claim it as sample rate. For example id a data logging system records 30 data channels, but reads each in turn only once per second, the channel rate is 30 per second, but the sample is only 1 per second."
"The data logging rate or speed (samples per second) is dependent on what data is to be logged. When logging engine data, 99% of the data changes no faster than about 5 times per second (one state to another and back).
The engine state is ultimately controlled by the driver’s right foot. The fastest external muscle in the humans is the eye-lid muscle. It goes through one blink-cycle in about 100 milliseconds.
A mathematician named Harry Nyquist found out (in 1928), that for anything you want to record, you only need to record at twice the maximum frequency contained in the recorded signal. So, for the human eye-lid, the required minimum logging speed is 20 times/second. The human foot, controlling a gas pedal, is much slower. Remember, the frequency is not measured from idle to WOT, but from idle to WOT and back.
The second parameter determining the logging speed is the statistical nature of the combustion process itself. No two combustion events in an engine are identical. Therefore, to get meaningful data, multiple combustion events must be averaged to see the overall effects. If each combustion event is analyzed and recorded, meaningful tuning data can’t be seen in most cases. At 6000 RPM an engine goes through 50 engine cycles per second (a 4-stroke engine cycle requires two rotations per cycle). At a logging speed of 12.5 samples per second this would mean that the resulting data is the average of 4 engine cycles.
The above means that data logging engine data needs to be done at 10-15 samples per second. Anything more creates only more data points which do not contain any additional information, but are harder to analyze.
The ByteTronik Data logging Hardware using the Siemens BMW/MINI specific KWP2000 protocol at 9600 baud rate thru OBD II port and using ByteTronik Data logging patch software in the ECU. Samples engine data between 8 – 11.5 samples/second. Without the patch software, it will log only 1 -3 samples/second using the factory Siemens BMW.MINI protocol at 9600 baud rate thru OBD II port.
When evaluating data-logging products be very aware of the difference between channel rate and sample rate. Many manufacturers specify the channel rate, but claim it as sample rate. For example id a data logging system records 30 data channels, but reads each in turn only once per second, the channel rate is 30 per second, but the sample is only 1 per second."
Thread
Thread Starter
Forum
Replies
Last Post
jetmechinnc
JCW Garage
28
11-18-2015 08:54 PM