moreover, the Modbus doesn't allow to have address 0 and you cannot set the address 0 via our DIP switches. When the DIP switches are in "0" position, the extension uses the address which is stored in the NVRAM, which, by default, is 15.
I'm sorry for not getting back to you in timely manner. This error is in the Evok and we have created a bugfix. Next week we will release a fixed package and if everything goes well today, the source code will be available on the Evok's Github.
hank you for your patience and have a good day,