Abstract: Test pulses representing bits combined in bursts are generated, defined in form and amplitude, and jittered, defined by reading curve shaped characteristic data and jitter identification data from digital memories, for the purpose of simulating defined cable types and lengths and are transmitted to a unit to be tested. In a receiver, the test pulse is received and forwarded by the unit under test are accepted for the purpose of a test and are compared to the test pulses transmitted by the transmitter.

Abstract: The test specimen is charged with an analog, preferably sinusoidal periodic test signal or, respectively, with the digital samples of such a test signal, whereby a numerical relationship exists between the period of the test signal and the system-inherent sampling period such that all sampling times lying within a predetermined test time span occupy different relative time slots in the periodicity interval of the test signal. Arising as a result thereof are a plurality of output information of the test specimen which, as a totality, describe the response of the test specimen to the test signal as precisely as desired. Said output information are, if need be after analog-to-digital conversion in a standard coder, deposited in a store and are available for identifying the desired properties of the test specimen, for example, the level-dependent distortions, by means of a computer.