S7-I and S7Plus Can1 Fixed Datastream - DBC

[stevieturbo]

With the datastream on the Syvecs, and the likes of the CAN layout AIM have for their dashes.....why do the slots not seem to line up ?

Even as low as say position 13. On Syvecs this is position Brake Light, but on the AIM setup Brakelight is clearly number 12 ? And the errors continue
How are they so wrong ?
Do "SPARE" positions not get transmitted or something ? hence positions fall back every time there is a spare/unused slot ?

Even the .dbc file here seems to have units/config missing ?

Does AIM have an ability to display Limp warning messages ?

syvecsaim.jpg (374.06 KiB) Viewed 15370 times

[jezzpalmer]

The S7-I and S7Plus Can1 Datastream is fixed so that with our plug and play kits users can't accident change items on the datastream which have a large effect on the Canbus for the Plug and Play kits.

Users can use Can2 on the S7Plus from pins B2 and B3 and this is fully programmed and can also support a I/O Expander.

Hi,

I am trying to attach an X10 to Can2 of my S7+ but as soon as I assign an IO pin from slave2 and program the ECU I get a an error saying "Calibration Error : GEN TX CAN - CAN Bus 2 not available" and the ECU is not in sync.
I’ve tried various things, I’ve discovered that If I set the frequency of all of the frames to 'UNUSED' for Generic Can Transmit, essentially turning it off, then SCAL will connect in Sync following programming, so I can use the X10.
Similarly, if I enable any of the CAN Receive frames I get a similar error.

From the line in the original post above "Users can use Can2 on the S7Plus from pins B2 and B3 and this is fully programmed and can also support a I/O Expander." it should be possible to achieve what I’m trying to do, but I can’t see how?

My configuration is..
Slave 1 – CAN 1
Slave 2 - CAN 2
Generic Transmit CAN 2
Generic Receive A, B and C all to CAN 2

Any advice on how to resolve this issue would be gratefully received.

Many thanks,
Jezz.

[stevieturbo]

I was under the impression, when a slave is used, like the X10 etc on the CANBUS, that canbus is then closed and cannot be used for anything else. It is dedicated to the expander.

Still not 100% sure then what the CANBUS on the expanders are for though, as I think they can only transmit, not receive. So some functionality is lost there.
Also not even sure what then is passed through to the expander if that is the case ?

CAN2 also gets locked to the expander, but CAN1 is still totally flexible where that is needed. I use this on my S8.

X10 on CAN2, but everything else, dash/gps, EGT on CAN1, all generic transmit/receive are on CAN1

On my S8 again with an X10, Slave 1 is CAN2, the only slave on my system. And Slave 2 is set to CAN3, not in use. Not even sure what CAN3 is

Obviously things are a little different with the S7 though.

And as usual....the FB group tends to get more response, always worth a shout there

[jezzpalmer]

Thanks for the reply, as always, Stevie.
That’s all marginally disappointing.

Can 1 on the S7 is used for the internal expander (Slave1), and only transmits the default fixed S7 stream; so in reality isn't that useable.

Using the S6 with X10 I do use the CAN passthrough via Can2 on the X10. The frame contents on this are configurable in SCal, pretty much like Generic CAN Transmit but with only 20 frames rather than 40. I use this to talk to my dash, HTG etc; but the S6 has not Can Receive.

I did post on one of the FB groups, but then I found this thread.

Cheers,
Jezz.

[stevieturbo]

When I used my S6 with the Plex dash, I was able to receive GPS and accell data from it ok

Although I didn't try anything else.

The last project I did, I asked about the S7's CAN....and came to the conclusion the S8 was just more flexible in this regard, so went with the S8 and a slave device on CAN2 ( Tim's MEU )

Maybe I'm wrong and the S7 can still be used with an expander though somehow. But I never got that impression it would do so as easily as the S8, and still remain quite flexible.

So the CAN on the expander just mimics the CAN1-20 slots ? but if used for a dash...would not be able to pass back on the receive side, even for GPS stuff ?

[TimH]

Warning - my information might be a few years out of date but I am 99.9% sure it still applies

The "slave" protocol runs in a non-standard fashion, at a non-standard data rate. It both transmits and receives "slave" data frames over the CAN link and is (pretty much) exclusively dedicated to that.

The ECU definitely can NOT receive any additional frames - so generic receive on CAN 2 is never going to work.

But you can use generic transmit to the X10, which will "down convert" to the standard 1Mbit/s CAN that you can connect to a dash...but still not receive anything.

S7 CAN1 is another enigma as it has a non-configurable CAN transmit stream; it sends the S7 "fixed" stream only and it can't be changed. But I don't know if you can do generic receive on it. That is definitely one for Syvecs to answer.

[jezzpalmer]

I understood that the X10 couldn't do CAN receive when used with the S6, but thought this was more a limitation of the S6; rather than the X10.
I'd rather hoped that the X10 would pass through the non-proprietary/generic CAN messages (both ways) after it has wrapped/unwrapped the 1.3Mhz slave specific protocol.

[TimH]

It's a limitation of the slave protocol rather than X10. Not enough bandwidth on the link to cope with much extra data.