tag out unused values

[jeroends]

Hello,
I fell into the following issue: for example. in my VR70 only 3 sensors are connected, so the other sensors give me a '-' in detection and forming ( [update notice] received read vr_70 SensorData QQ=10: 20.44;-;-;-;20.06;20.25;c8 7c 00 ).
When I want this unit to be used in Openhab, through the Homeassistent auto config, this gives me a sensor whith a NULL value because the json translation can't figure out what to do with the '-' in the value.
So my question is: can some sensor values be tagged out or be given a fixed value (ex. 0) to get around this problem because this is not the only value with this problem? My logfiles are getting very very big. (of course a work around could be to add every sensor manually).