In a method and device for correction of a B0 field drift in a temperature map acquisition by magnetic resonance tomography, a fluctuation measurement is calculated per pixel from a number of magnetic resonance tomography phase images of an examination subject or from temperature maps derived therefrom. A first signal path extends from the output port of the amplifier to the ground in the first impedance matching circuit. The interface device has two inputoutput ports for communication to a PDA. And, shutoff switches switch off the electronic switches respectively when a voltage generated in the excess current detecting devices exceeds a predetermined value. Additionally, the information exchange instructions may be executed by the implantable pulse generator to extract the network routing information if available and the transport control information from incoming packets and to reconstruct the data from the packets and provide the data to the one or more application programs. Particularly, reduction of margin of the clock count due to error between the delay time in the delaying circuit and the time to be compensated can be prevented by independently counting the internal clock and the inverted internal clock.