Filling level measuring system and method for transmitting test signals in such a filling level measuring system

摘要

The method described enables reliable, meaningful testing of a filling level measuring device by means of a test and measured value transmission which is secure against falsification. The test command can be formed by means of amplitude control of the current flowing between the limit switch and the evaluation device to a value lying outside the measuring current region but which still lies above the intrinsic current requirement of the limiting switch.