Hello again @JasperJackson,
as we discussed via email, the image 1.7 and latest development version of MervisIDE fixes the problem you have encountered. Another problem occured when reading states of the digital inputs. We discovered a problem in the installation package and issued a new version. To fix your problem, SSH into the PLC and issue these commands:
@TomasKnot Hi Thomas! Thanks for the extensive reply! Really cool! I didn't think of the modbusserver solution, it sounds way more compatible and standard than the way through the HMI api. But i'll wait for the BacNET/IP interface, that sounds even better. I'll finish off the Python plugin for Domoticz anyway, it works great already with booleans and is even bidirectional :), next step is to add analog values... Thank you!