Thanks becky for your reply!
Meanwhile I made an experiement:
I had the thought that I don’t necessarily need one aplikation to do this, but that I can take one normal application and the configuation tool (wizconfig) at the same time.
I had my own application for a WIZ750SR-485, where i plugged a sensor in that gives 10 values / messages per second on the RS422. I started my application to read them via ethernet and show them on the screen.
WHile this was running, I started wizconfig - and it found the device and read all of its configuration without problems. It even showed the values of the analog Inputs of the GPIO’s in 1 Second intervalls.
However - when I tried to configure something - even only the state of an GPIO, either the application or the wiz750SR crashed. In one case it crashed so that the PHY-LINK and TCP-CONNECT where still on and it didn’t make a bleep and I had to reset it manually.
So it seems to me that is is at least possible to read the configuration and the GPIOs of the device simultaneously to communicating on the UART.
But this doesn’t seem to be the intended use of the device - so I decided not to use this in my application.
It just doesn’t feels save enough.