Hi

I'm using CM CANOpen in Transparent mode with S7-1200.  I'm reading Received CAN messages each cycle times and sending CAN Messages using interrupt(as I need to send them on regular intervals).

Using this configuration It looks like that when interrupt happens while reading incoming CAN messages it destroys my received CAN messages.

Does anybody has suggestions whats going wrong? any refer to documents covering this problem? How to fix this?

Thanks in advance.

Hello,

maybe better explain what you mean with destroy. Your data will come to some buffer? Pls explain better.

Hi Duris,

Thanks for your reply,

Yes I'm using a buffer for nineteen CAN2.0 frames(each 12 bytes). One byte in received messages is kind of counter. I'm using the counter to realize if some frames are missed. CAN frames are coming in by constant rate of every 16ms. In my Debug connection I see that all my statistics data are updated constantly and no gap is seen(as far as human can see). 

I think my received frames are "Destroyed" because my counter all of sudden jumps a big value(say from 0x08 to 0xfe) . by having a increasing counter every 16ms, this should mean 3~4 Seconds of bus freeze which is not what I see. 

So I can think of two possible scenarios 1) My received frame has been destroyed and counter is not the value published on bus  2) I've received the CAN frames not in order

Still I haven't been through the outgoing CAN frames to see whether they are distorted or not.

Hello,

maybe this link can be helpful: CanOpen Example / Basics

Update: also what I saw is Little/Big Endian difference to f.ex. Profibus/Profinet.

Thanks Duris,

Example provided in the link is CANOpen, I'm using Transparent mode. Problem is not Little/Big endian as I have ~well establish communication over CAN,

Thanks for your time.

Hello,

aaaaaah sry for missunderstanding. In this case I'll be not helpful, also don't have test HW. Hope you'll find solution so soon.