CAN Channel assignments

[Rex-Racer]

I want to create a custom CAN template for my AIM MXG dash and use that as my primary data recorder. The AIM has a default M1 template but does not have the CAN channels for the PDM. Where do I find a list of the transmitted CAN channels address, length, bits etc for both the M1 and the PDM?

[David Ferguson]

The PDM CAN Transmitted information is found in Appendix 2 of the PDM User manual. You can download that from here:

https://www.motec.com.au/downloads/downloadmanuals/

My suggestion is to connect the MXG CAN2 and CAN1 together, and use the built-in template for the M1 (on CAN1), and configure your custom PDM template for CAN2.

[Rex-Racer]

I didn't know you could do that. Hmmm....never thought about doing that. That just might work.

The problem arises when there are channels I want to log in the MXG that are not in the base CAN setup of the AIM, brake pressures for instance. Now, I could hook the brake pressure sensors to the AIM but I would rather it go through the MoTeC so it can then change the brake state which is transmitted to the PDM where it will turn off/on the brake lights. There are also channels in the AIM ECU CAN setup that I don't need. This is why I would like to build my own custom ECU CAN1 setup for the AIM. It seems most, if not all, of this information is already setup to be transmitted over the CAN Bus. So my question remains:

1. Is there a list of the CAN channels with IDs and so forth out there for public consumption to allow logging outside the MoTeC ECU?
2. For a channel like brake pressure, is it possible for the end user (one that does not have M1 Build) to assign a CAN output channel for that value?

[David Ferguson]

The Motec M1 sends the Brake Pressure Front and Brake Pressure Rear channels on ID 655, bytes 0-1 and 2-3 respectively (1kPa per bit). I think there are two ways you can learn about what channels the M1 transmits -- one, look at the source code in M1 Build (I already advised you of this); the second is to look at the M1 Templates in a Motec Dash config (for example, install the C125 Dash Manger, then configure a CAN Communications for the "M1_General_0x650_Version 4"), and look at the channels received there, use the "Edit..." button to dive further into what Id's and offsets are used for each channel.

You could add reception of ID 655 to your custom template to receive channels that the standard Aim template doesn't (they have a limit of 64 channels per ECU template, and they don't receive all the channels the M1 is capable of sending). There is one of the areas where a MoTeC dash / logger is far superior to the Aim MX* series loggers.

Good Luck with your project.

Oh, to answer your questions:

1. I don't believe there is a published list. See above. I believe if you write to support@motec.com they can send you a .dbc file (if you know how to deal with that) that documents the can messages.

2. No. there are not currently any "configurable" CAN output channels. But since you have a development license you could create such a thing. Please share when you have it done.

[Rex-Racer]

Thanks for your help David, appreciate you taking the time to answer my questions.

I was able to find the .dbc file but not sure how to open it.

I don't have a development license, just an end user that is new to MoTeC and trying to learn this powerful system. At times I feel I'm in a bit over my head but I like the challenge. I may, at some point, need to hire someone to get me setup as there is a bit of a learning curve to all this.

At some point I may move to the MoTeC dash but for now all my previous data and all the data I share with others are all in the AIM family so it makes it easier to compare data.

[adrian]

Kvaser have a free dbc file editor that you can download from here.

[David Ferguson]

Thanks for your help David, appreciate you taking the time to answer my questions.
...
I don't have a development license, just an end user that is new to MoTeC and trying to learn this powerful system.

My apologies, I confused you with this thread... viewtopic.php?f=53&t=3860

[gkwestfrank]

i found the AiM logger product is really limited on the feature and/or whoever doing the CAN template wasnt doing their best(mxg max ch is 120 per CAN and the m1 temp only use 73, if you wanna know, M1 is sending over 200 ch out). whoever have worked on a GT4 car(audi r8 gt4, bmw m3 gt4) will tell you the same thing, it is filled with bug and speed is not up to par. and let me ask you this, even if you can write the custom CAN at the M1, how are you going to get that into the mxg? do you have what it take to program them into the mxg? have you tired?

[Rex-Racer]

i found the AiM logger product is really limited on the feature and/or whoever doing the CAN template wasnt doing their best(mxg max ch is 120 per CAN and the m1 temp only use 73, if you wanna know, M1 is sending over 200 ch out).

There's no question the MoTeC dash would be much better. At some point I will likely go that route, but for now, I've got a complete redo of the electrical from the battery to the ECU and PDM, complete rewire, new ECU to learn, new engine going in, need to learn the paddle shift part as well. Complete tear down of the car. Budget is a factor here the dash is another expense right now. Plus, I am trying to run ALL my sensors through the MoTeC M1 so that when I do switch over, all I'm doing is removing a logger and display for the most part and won't have to rewire much at all. The only sensors I will likely run in the AIM are the shock pots.

Let me ask you this, even if you can write the custom CAN at the M1, how are you going to get that into the mxg?

Race Studio 3 has the ability for the user to write a custom can configuration. I write that, select MoTeC as the ECU and as long as I know the CAN parameters of the channel, no reason it shouldn't work. One concern is if AIM software will "let" me do what I want. I already use it for CAN tire and brake temp sensors and it works just fine. The AIMs 120 ch limitation likely won't be an issue for the CAN 1 bus, AIM's CAN 2 bus has an 80 channel limitation so good planning should allow me to see the channels I want to see and log. I also have a Telemetry box and want certain channels there as well. But the main thing is to be able to log the M1 channels AND certain PDM channels as well as my CAN sensors for data analysis and Telemetry.

Do you have what it take to program them into the mxg?

That, sir, is an excellent question...we'll find out

Have you tried?

For the MoTec? No. For other CAN devices, yes and after some trial and error and reading and asking questions, I was able to get where I wanted.

Is this more complex? Sure is
Is it doable? Don't know but logically from what I've seen it should be. I'll find out soon enough.

[gtihk]

David,

What does the value of VCSCompound represent please?
Do you have a sample Scheduled Function for a modified Transmit VCS you could send or post?