ATE-based functional ISDN testing

It is pointed out that, when creating an ATE (automatic test equipment) test environment for the functional testing of an ISDN (integrated services digital network) device, many diverse control and data functions are required to mimic the operation of a far-end device. Among these are data conditioning (scrambling), waveform conditioning (transmission line simulation), and time base conditioning (jitter). Methods are described for the straightforward implementation of these functions. These methods distribute the tasks of waveform generation and analysis to specialized instruments. This approach frees the digital pattern from the task of tester `housekeeping´ and establishes the various forms of signal conditioning as independent functions, thus greatly simplifying the overall test program and allowing the application of standardized pattern generation and debugging tools. It allows for greater software modularity and portability