How to disable FlexCAN auto re-transmitting feature

YuhuiMa — Tue, 08 Dec 2020 03:22:38 GMT

Hi,

My goal is to let FlexCAN always only send single-shot CAN message.

I am currently using S32K144 SDK to play with FlexCAN.

The current situation is, when a CAN message was not acknowledged by any receiver or any error was reported, the FlexCAN will repeatedly re-transmit this CAN message until it's ACKed or timeout.

For some CAN messages, I just want FlexCAN to send message frame only once without any re-transmitting. Where is that magic reg/bits?

Plus, much appreciate if you could provide an example code on that. (I am just new to S32K)

Thanks

Re: How to disable FlexCAN auto re-transmitting feature

lukaszadrapa — Tue, 08 Dec 2020 08:59:07 GMT

Hi Yuhui,

there's no such option, this behavior is given by CAN spec.

Solution is to connect another node which will acknowledge the message.

Or, if it is for test purposes only, you can use internal loop back mode (LPB bit in CTRL1 register). In this mode, you will receive what you sent and ACK is ignored.

Regards,

Lukas

S32KのトピックHow to disable FlexCAN auto re-transmitting feature

How to disable FlexCAN auto re-transmitting feature

Re: How to disable FlexCAN auto re-transmitting feature