CAN message ID's

Jo Van Ranst

Other Parts Discussed in Thread: HALCOGEN

Hi, I have more of a question, that might be a problem.

I'm building up a CAN network in electric car BatteryManagmentSystem. This is made up of a HighVoltage Box and a Slave measurement system per 12 battery cells.

The problem i'm facing is the possible message ID's. Each slave will send about 80 bytes of data, meaning 10 ID's per Slave: example Slave1 => ID= 0x100 - 0x109 => Massage Box 1-10.

Now this would mean that with CAN1 there could be a max of 6 slaves, that is not a lot.

Can't I use 1 message box per Slave?

ID = 0x100 - 0x109 with Mask 0x7F0. So all messages from slave 1 arrive in the message box. But how could you get the received message ID?

Or is there a better way to do this?

Thanks in advance,

over 11 years ago

0 Enrique Lizarraga over 11 years ago

TI__Expert 4580 points

Hello:

We have received your question and will come back soon with our feedback.

Thank you.

0 Enrique Lizarraga over 11 years ago in reply to Enrique Lizarraga

TI__Expert 4580 points

Hello:

Receiving multiple ID's into one mailbox is the right approach. The only risk would be to lose messages in case your are receiving them too fast, but as you are limiting one mailbox per slave that shouldn't be the case (unless the slave is too fast).

About the IDs, those can still be read from the mailbox.

Regards.

0 Jo Van Ranst over 11 years ago in reply to Enrique Lizarraga

Prodigy 40 points

First of, thanks for the quick response.

But how do you get the ID's from the mailboxes? The functions provided by Halcogen doesn't return the received ID, does it?

uint32 canGetData(canBASE_t *node, uint32 messageBox, uint8 * const data)

Or is it embedded in the 'data'?

Thanks in advance,

0 Enrique Lizarraga over 11 years ago in reply to Jo Van Ranst

TI__Expert 4580 points

Hello:

You can use canGetID(canBASE_t *node, uint32 messageBox) to get the ID.

Regards.

0 Jo Van Ranst over 11 years ago in reply to Enrique Lizarraga

Prodigy 40 points

Sorry, seem to have missed that.

Thanks for the help.

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CAN message ID's