CAN values differs from TunerStudio values ?

This is a forum for discussing the development and testing of alpha MS2/Extra code. Documentation
(Runs on MS2 and Microsquirt)

Moderators: jsmcortina, muythaibxr

Post Reply
Manu
Master MS/Extra'er
Posts: 723
Joined: Mon Feb 15, 2010 4:57 am
Location: Alès - France
Contact:

CAN values differs from TunerStudio values ?

Post by Manu »

Hello,

I was testing some CAN functions on a dashboard this afternoon and found some differences between what TunerStudio display for looptime and dwell values and what was displayed on the dash. So I took my CAN dongle and do some tests. I noticed that dwell and looptime values aren't similar between what TunerStudio 2.6.19 display and what CAN software display (ETAS BusMaster).

Image

I also try to look at MS2extra Code. CAN_looptime is outpc.looptime and CAN_dwell is outpc.coil_dur.
Some differences for dwell :
TS : CAN Busmaster
5.3 : 8.0
5.4 : 8.1
6 : 9
7.1 : 10.5
8.1 : 12.2

for looptime :
300 : 500
1000 : 2000

Can someone have a look at this please, I really want to know if it's an hardware problem from my side.
Regards,
Manu
I can supply, repair or upgrade Megasquirts in FRANCE.

Image
https://www.megasquirt.fr
Alfagta
Experienced MS/Extra'er
Posts: 239
Joined: Wed Aug 21, 2013 2:54 am

Re: CAN values differs from TunerStudio values ?

Post by Alfagta »

Would be better if you are tell us the raw can data. We dont know how you translate the data.
Post the can bus message with hex data values.
Alfa 156 GTA
Alfa 75 Race Car MS III -- alway latest FW
Alfa 164 V6 Turbo
Alfa 155 2,5TD RIP
Test MS II --always latest FW
Tunerstudio V2.6.11 Registered
MegaLog Viewer V3.4.04 Registered
Manu
Master MS/Extra'er
Posts: 723
Joined: Mon Feb 15, 2010 4:57 am
Location: Alès - France
Contact:

Re: CAN values differs from TunerStudio values ?

Post by Manu »

Alfagta wrote:Would be better if you are tell us the raw can data.
In the picture provided in first post you can see :

For Dwell :
TS dwell : 4.1ms
RAW Can Data : 3D
Translated CAN Data : 6.1ms

For Looptime :
TS looptime : 918us
RAW Can Data : ABB
Translated CAN Data : 2747us
Alfagta wrote:We dont know how you translate the data.
As per DBC file and Jame's CAN Broadcasting PDF.

i.e : Dwell : ID = 0x5F9
Offset = 0
Factor : x0.1
I can supply, repair or upgrade Megasquirts in FRANCE.

Image
https://www.megasquirt.fr
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: CAN values differs from TunerStudio values ?

Post by jsmcortina »

On MS2, times are in timer ticks of 0.666 microseconds. If that impacts any of the interesting ones (such as dwell) that should probably be fixed. The CAN broadcast code is mostly a direct port from MS3 where the timer ticks are 1.0 microseconds.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Manu
Master MS/Extra'er
Posts: 723
Joined: Mon Feb 15, 2010 4:57 am
Location: Alès - France
Contact:

Re: CAN values differs from TunerStudio values ?

Post by Manu »

Thanks James.

This make sense with dwell (6,1 * 0.666) = 4,0626, which is near from 4.1.

But for looptime it sound out of expected results => (2747 * 0.666) = 1829,5. This is near double from what TS say.

If there is a solution that I can apply in the DBC, this will be enough for tests I currently do.

Bests,
Manu
I can supply, repair or upgrade Megasquirts in FRANCE.

Image
https://www.megasquirt.fr
Post Reply