@Dmytro said in Error: "Write of group with index 3 skipped":

Write Only On Change || False

In a previous post was a mistake. Write Only On Change || True
It causes error "Write of group with index 3 skipped"
If that parameter has value False, error message in Port monitor disappears.

Instead of that, Port monitor shows to me another problem:

15.12.2021 14:37:40.0122 => Send: 240 16 6 3 0 1 2 3 0 201 7
15.12.2021 14:37:40.0822 Timeout
15.12.2021 14:37:40.0922 => Send: 240 16 6 3 0 1 2 3 0 201 7
15.12.2021 14:37:40.1622 Timeout
15.12.2021 14:37:40.1722 => Send: 240 16 6 3 0 1 2 3 0 201 7
15.12.2021 14:37:40.2422 Timeout
15.12.2021 14:37:40.2672 => Send: 240 3 0 0 0 66 208 218
15.12.2021 14:37:40.3372 Timeout
15.12.2021 14:37:40.3472 => Send: 240 3 0 0 0 66 208 218
15.12.2021 14:37:40.3652 <= Recv: 240 16 6 3 0
15.12.2021 14:37:40.3722 <= Recv: 1 228 96
15.12.2021 14:37:40.3722 Timeout

So I still cannot write the value to the register.