Well, I did not get any replied but I know the answer to this question now.
RRC micro works well with IC7100. At first it seemed that I did not have any audio output from the radio coming through. But then using radio control software (HRD or TRX Manager) I noticed that AF sets at minimum each time radio starts from RRC micro.
So it is always necessary to set radio audio level as required.
Otherwise no issues so far
73
Mirek
VK6DXI