The digital function generator model DFG-500 supplies the Mössbauer Driving System with the reference signal, which determines the waveform of the source motion. With SINE and TRIANGLE (CONSTANT ACCELERATION) the most commonly used waveforms are available. They are stored digitally and are converted to a highly precise output signal by means of a Digital-to-Analog Converter. Besides the analog output signal, the unit provides digital control pulses which can be used to synchronise other instruments. The START and the CHANNEL ADVANCE outputs provide synchronisation signals especially for multichannel analysers.