We have a SDO transfer performance issue. Our MN is a Linux Preempt-RT and CN is a NIOS II (based on cn-dual-hostif-gpio demo).
We use a SDO domain to transfer a file (in blocks of 1000 bytes) to a custom object (5F50), but each transmission becomes slower and slower. So, we used Wireshark to capture the trafic. We found that each block is fragmented in 256 blocks (so 4 frames). At the end of the transmission, Wireshark prints the following message "Illegal Message Fragment" (see attachment).
EDIT: add a Wireshark extract
My questions are :
Why are 1000 bytes blocks fragmented in 256 bytes blocks (MTU is 1500)
Why does Wireshark print the message "Illegal Message Fragment" ?
Hello,
We have a SDO transfer performance issue. Our MN is a Linux Preempt-RT and CN is a NIOS II (based on cn-dual-hostif-gpio demo).
We use a SDO domain to transfer a file (in blocks of 1000 bytes) to a custom object (5F50), but each transmission becomes slower and slower. So, we used Wireshark to capture the trafic. We found that each block is fragmented in 256 blocks (so 4 frames). At the end of the transmission, Wireshark prints the following message "Illegal Message Fragment" (see attachment).
EDIT: add a Wireshark extract
My questions are :
Thank you !
Best regards.
Corentin
Last edit: Corentin GUILLEVIC 2018-12-17
Hi,
In the wireshark trace, I see some duplicate frames sent by the MN even if the CN replied by a SDO Response transfert OK (expedited transfer).
What can trigger such duplicate frames ?
Note: The OPLK stack is 2.6.1 on MN and CN.
On the host, the ethernet controller is a i210 Eternet chip.
Best regards,
Romain
Hi,
Here a debug trace.
Best regards.
Corentin