Both a wireless terminal apparatus and wireless base station apparatus are provided that can, in an operation of encoding the control signals of the upstream link transmitted from the multiple terminal stations while encoding with regard to each of the terminal stations, increase a number of the terminal stations to which different codes are respectively assigned. The system includes at least one medical device operable by the controller. The requirement for manufacturing accuracy and the effort required for assembly of the silent chain are reduced. Whereby, in order to test whether a signal connection is overmodulated, the input voltage value at this signal connection is converted to a digital data value which, because of its final bit width, lies within a data range limited by an upper and lower data limit value. The replication of data is managed by the plurality of pluggable services using the change log.