Missing 1st 16 Messages replayed into FD Router

[alan eastwood]

This is a follow up to the message posted by dbelton on Thu 11. May 2017, 12:37

I am planning to use the Router FD as a speed converter to change from variable bit rate FD messages to fixed bit rate messages FD that are then input into an FPGA where they are sampled and stored. The FPGA is dumb and does not acknowledge the messages and is the only device on the second bus. I could add a second device to the bus, but it is overkill for just an acknowledgement bit driver.

Is it possible by using custom firmware in the Router FD to turn off the ACK mode of the transmitter so that the message is not resent when the ACK bit is not received?

We have the above set up working, the messages are captured and stored. The problem is that when we replay the sampled messages back to the FD Router then the first 16 appear to be ignored.

Does anyone have any suggestions as to why this may happen.

many thanks in anticipation
alan

[PEAK-Support]

How do you "play back" the CAN FD Frames and who stored them ? The Router FD itself have no SD card.
Please try tro explain first your setup (maybe a sketch help?) and what exact you have done.

[alan eastwood]

Hi, thanks for the quick response...

Our equipment is to capture and replay CAN frames from a live bus. We are testing with a PCAN USB FD device connected to CAN2 of the router and our record/playback device connected to CAN1. The PCAN Router is programmed to pass messages from the PCAN USB FD device to our device and vice versa. During recording our device captures the CAN frames as a synchronous stream from the router, and during playback the bitstream captured is simply transmitted back to the router. We have a PC connected to the the PCAN USB device which communicates with the CAN Bus using PCAN View.

After the initial issue with the 16 messages, we have proved the functionality with 2500 messages per second being recorded and successfully played back and captured with PCAN View.

We have a workaround where we send out 16 dummy messages after start up, but are keen to understand why the first 16 are not successful. We see them being transmitted to our equipment, and being transmitted back to the router, but they are not passed to the router software as messages, or errors.

Hope this is clear enough to explain our set up.
thanks
alan

[PEAK-Support]

We do not understand the reason why a PCAN router is between the PC CAN Interface and your Data Logger ?!?
We also do not know what exact is when powered on , you need to understand that the PCAN-Router FD need some time after power up to load the FPGA CAN Core etc. if you directly stert sending after power on, it could be that some Messages are lost..But without more information about exact setup (maybe a sketch that shows which CAN module work in which mode, which Software is running on which unit ertc.) it is hard to help. You also could contact us per e-mail: support[at]peak-system.com