The PPG 512 is based on a programmable waveform generator, that permits to generate pulse patterns in a cyclic sequence of 512 bytes. The 512 bytes are stored in a special high-speed memory that can be read out at the full speed of 5 GS/s. This results in a timing resolution of 200 ps per byte (other values possible on request). By loading a data set, arbitrary pulse sequences can be defined with an amplitude resolution of 8 bits (0 to 255). This pre-defined sequence can then be run as a gapless loop at the full speed of 5 GS/s or started and stopped by an external control signal.