Abstract: The present invention discloses a device for converting a digital input into an analogue output, comprising means for generating a binary pulse signal in dependence on said digital input, a filter for filtering said binary pulse signal to obtain said analogue output where the level of the analogue output depends on the relation of high and low level pulses of the binary pulse signal during a period and the precision of the analogue output depends on the number of binary pulses during the period. The high and low level pulses in the binary pulse signal are spread through said period.

Abstract: The description covers the identification of the position of data packets (P1, P2, . . . ) which are located in a serial received data stream and each have check data in a check field and a check sum (CRC) which is formed using the check data, the received data stream being passed in serial form through at least one comparison unit (9) which forms a new check sum (CRC′) with each received signal to be newly added and compares this new check sum with data which are looked at for the associated received check sum (CRC), and, furthermore, during the comparison, the influence of all data is eliminated which do not belong to the check data and to the check sum (CRC).