Program stopped - do not understand the cause

Hi,
I have a problem I am not able to figure out at all. So, I need some help.

I have simple 4 axis controller build on MESA 7i96S.
I have only stepper motors connected phisicaly. Forth controller is not connected.

I am running this machine fine for most of the time. 
But sometimes I am getting this (error message in the right bottom of the screen):

"hm2/hm2_7i9666666s.0:Watchdog has bit (set the /has-bit.pin to False to resume)"

below this is second error message:

"Unexpected realitime delay on task 0 with period 1000000
This Message will only appear once per session.
Run the Latency Test and  before continuing"

I find LinuxCNC in a state of e-stop and machine not running. But position where program is interrupted is not necsarely concistant with phisical position of the machine.

If I get controller from e-stop state jogginf works in the controller but machine does not move.

What can be the cause and nature of this problem?

Cris

 

This indicates a loss of communication , most commonly this is a real time issue
with the network connection.

Typical fixes for network real time issues:

If you host computer uses a RealTek Ethernet chip, it's likely you need to install the DKMS 8168 driver.

If you have a Intel Ethernet chip, disabling IRQ coalescing helps (see hm2_eth manual page)

To tesl network latency, run this command:

sudo chrt 99 ping -i .001 -q -c 60000 [card_ip_address]

This will run for 1 minute and print timing statistics.

Where [card_ip_address] is the 7I96s card ip address (192.168.1.121 or 10.10.10.10)