Man Roland 500 Coating section problem

Hello. Man Roland 500, 5+1. Problem with the coating module. Error "Drive 4, communication fault."
and "Drive 5, communication fault." At first, this error was not present at every boot.
At boot, the coating module could turn on and work or show this error and not turn on.
Now, for several days, this error is always there. This module has LUST VF1402 pump drives.
From the front panel Type: KP100, both drives start and do not record errors.
Has anyone encountered such a problem?
Please tell me where to look, which boards are responsible for the communication Drive 4 and Drive 5.

 

Year of manufacture or series of the machine. Take a screenshot of the errors or error numbers.
If the problem is Lust, they should be replaced or repaired, if still possible. If they are given for repair in time, there is no problem with the repair. If the machine is restarted for a long time to start, they become unrepairable.
Call if you still speak Russian ... or German, English ...

 

We do not reboot the machine to start the varnish, at the beginning of the shift the machine turns on and works as is with or without the coating section.
Could both drives fail at the same time? The drives themselves do not record errors when starting, the green blinks and the red lights up, which shows that the drive is ready for work.
"Drive 5, communication fault." does this error mean that there is no communication via CAN bus? Perhaps the problem is with the CAN bus board in the drive, but why in both? Is there any way to check this?

 

The two inverters are connected in series. If there is a problem before them, both will not work. Check the communication cables. It is possible that they have lost addresses. The easiest way to check is with Downloader. It is normally installed on the central console. You must log in as sofronica.
The machine is very old. If the firmware is not updated, addressing is difficult with the 2002 software.