output signals f and g are directed to the two inputs of the downstream up down counter 8 in such a way that the counter status is incremented by 1 when signal a in the trigger 6 exceeds the positive threshold value and decremented by 1 when signal a in the trigger 6 falls below the negative threshold value the seven highest valued bits of the 9 bit up down counter 8 are directed to the counting selector 9 and evaluated at a specific time which is determined via lead b of the up counter 10 the up down counter 8 is stopped during the period of evaluation the result of the evaluation pal and secam or ntsc 4 4 and ntsc 3 5 is present at outputs c and d a further control signal from the counting selector 9 is directed to the h 2 switch 11 by means of connection e this serves for the phase adjustment which is carried out when the counting selector 9 has registered a certain number of negative counting pulses within a vertical period this signifies that although a signal capable of evaluation is indeed present at circuit point a the phase angle of the h 2 switch 11 in the receiver does not coincide with the phase angle of the h 2 switch of the transmitter the essential function of the counting selector 9 is to decide whether a chromaticity signal f capable of evaluation is present at the input to the identification circuit and to which transmission standard if applicable it relates.