error finishing read!

Hello, I'm new to this forum and this is my first post. After a quick read and some YouTube videos, I installed the latest LinuxCNC ISO (2.9.2) and created a first configuration with the PnCconf. The connection (ping) to the 7i96s works. I was able to read inputs. I connected a JMC closed loop motor (step/dir and supply voltage). The settings for the motor also seem to be correct, it turns once when I let the machine move 5mm. Unfortunately, this error then appears quite soon:
hm2/hm2_7i96s.0: error finishing read! iter =....
The INIT diode on the mesa card then lights up red and LinuxCNC has to be restarted.

Sometimes this error also occurs:
motor 0 position error

Another strange behaviour occurs after moving one step (5mm, 1mm, ... ), the controller always switches off and I have to press the switch-on button in LinuxCNC again so that the controller is on again and I can move the axes for a short time.

best regards Anton
 

This is most likely a latency issue

1. have you run a latency test?

I would suggest "latency-histogram --nobase --sbinsize 1000"

2. Have you disabled all power management options in the BIOS setup?
This include turbo modes, EIST, Cstates > C1, Cool&Quiet etc, basically
anything that causes the CPU to change speeds dynamically or sleep.

3. Also in the BIOS you should disable hyperthreading and any management
engine  related  options that affect the network (like AMT)

4. If your PC has an Intel Ethernet chip make sure you disable IRQ coalescing
(man hm2_eth)

5. Pinging the 7I96S will give you some idea of network latency
(this example assumes the 7I96S is set for a 10.10.10.10 IP address)

ping -i .2 -c 4 10.10.10.10
sudo chrt 99 ping -i .001 -q 10.10.10.10
 (let the last command run for a few minutes and
then stop it with a control C, it will print timing statistics)

If  BIOS changes and disabling IRQ coalescing do not help, the next step is to try
changing the kernel command line options, using isolcpus to isolate one processor
for real time use and pinning the Ethernet IRQ to that processor.

Thank you very much for the quick reply.
Regarding 1) I looked at the jitter in the latency test and it was in the very good range. I am using a laptop (i7), could this be an additional problem? In Linux I switched off everything that could be switched off there via power options. I have not yet made any settings in the bios.
I will go through points 2 to 5 tomorrow.

I only have basic knowledge of Linux so far and, as already mentioned, I am an absolute beginner in the field of Linux cnc. If steps 1-5 don't bring any improvement on my laptop, I would contact you again about the kernel swap, I don't know how to do that now. 

Best regards from Marburg
 

Unfortunately laptops are usually not good real time hosts for LinuxCNC
because they often have power management features that cannot be disabled

That said, some are OK

Good morning.
I have gone through points 1 to 5.
to 1) see histogram in the appendix
2) I cannot change any of the properties mentioned in the bios.
3) There is also no way to deactivate hyperthreading.

to 4) I have read hm2_eth. In the file /etc/network/interfaces there was only the loopback interface. I added eth0 there (see picture in the attachment). The entry is probably wrong because I don't have eth0. My interface is called enp5s0 !?

to 5)
 a) ping -i .2 -c 4 10.10.10.10
    -> min: 0.093 avg: 0.135 max: 0.240 
b) sudo chrt 99 ping -i .001 -q 10.10.10.10
   (see picture in the appendix)


Best regards

No, I am already pinging from 192.168.1.120 to 192.168.1.121. In the text, I accidentally copied the IP from the PCW instructions. The ping works, it is probably a latency problem.

Thank you very much, I will give it a try later.
Unfortunately, I can't evaluate the result of the ping and the histogram.
Which value is too large and how large should it be? best regards