Bugfix invalid voltage / temperatur after coldstart: In case of a cold start (complete power on / off) the RTE could send devie data before values like voltage or temperature have been measured for the first time. As result the device history data was set to it limits causing a minimal voltage of 2V to be displayed in history memory. Workaround for voltage is to initialize it to 6V at startup but for temperature a default value having no impact to the history memory is not possible