mesa setup 7i98 with 7i88, 7i89, 7i74, 7i70, 7i72 & 7i73

Ping is around 0.1ms. Max latency on this computer is around 20µs for the servo-thread which is truly quite much.
What latency would be the limit for this kind of setup?

20 usec latency is fine

It does seem like a dropped packet issue

What is the host Ethernet chip?

Intel chips need to have RX IRQ colalescing turned off

(man hm2_eth)

I kept the latency test running during browsing and the latency does get higher. I have also seen 60µs. I guess more would also be possible. Not sure when this could become a problem.

I have two Reaktek network chipsets in this computer. Not sure which is actually connected to the 7i80:
RTL810xE/RTL8169

I still set the irq-thingie and nothing really changed. I have attached another output file. After enough tries it seems to register but this it not a solution.
I wonder if my diy-flat-cables could be a problem? Are shielded-25pin cables necessary?

best regards,
Alex
 

One of the SSerial cards is failing to register on time, so i would disconnect one by one and check if the error disappears.

Flat cable could be an issue (it was in the past before digital filtering was added to the UART
RX) But if you have a current bitfile (newer than a couple years old) even a 10 foot flat cable should be OK

IRQ coalescing does not affect the RealTek driver

@tommylight:
I didn't get smarter after disconnecting single devices. The problem seems to be quite random to me. I just ordered a new set of cables just to make sure (RJ45 and 25pin).

@PCW: You have compiled my bitfile in March, so it should be fine... but anyways I will just make sure it is not about cheap cables. I will know more in a week.

I would try another PC host as it still looks like a global problem of some kind
(like dropped packets)

Found the problem before my new cables arrived. I couldn't use another pc but I just swapped ethernet-ports. Now I am using the on-board lan for 7i80 and the pci-ethernet card for lan/internet.

Tada: connection is stable and mesa cards work great ).
Thank you very much for your support!

Now I am already struggling with encoder input configuration but I'll ask after I have checked my hardware - maybe the encoders are the problem.

Thanks & best regards,
Alex