Abstract: A coupling unit is adapted to be coupled between a first and a second unit to be tested. Said coupling unit comprises a first signal path that is adapted to provide a signal connection between at least one terminal of the first unit to be tested and at least one terminal of the second unit to be tested. The first signal path comprises a signal conditioning facility adapted for receiving a first signal from the first unit to be tested, for conditioning said first signal in accordance with predefined parameters, and for providing the conditioned first signal to the second unit to be tested.

Abstract: A coupling unit is adapted to be coupled between a first and a second unit to be tested. Said coupling unit comprises a first signal path that is adapted to provide a signal connection between at least one terminal of the first unit to be tested and at least one terminal of the second unit to be tested. The first signal path comprises a signal conditioning facility adapted for receiving a first signal from the first unit to be tested, for conditioning said first signal in accordance with predefined parameters, and for providing the conditioned first signal to the second unit to be tested.

Abstract: A coupling unit is adapted to be coupled between a first and a second unit to be tested. Said coupling unit comprises a first signal path that is adapted to provide a signal connection between at least one terminal of the first unit to be tested and at least one terminal of the second unit to be tested. The first signal path comprises a signal conditioning facility adapted for receiving a first signal from the first unit to be tested, for conditioning said first signal in accordance with predefined parameters, and for providing the conditioned first signal to the second unit to be tested.

Abstract: A testing apparatus and method for testing of assemblies (BG1, BG2 . . . , BGn) in digital electronic systems, which permits a test on a system level without a fixed pre-setting of the number and position of the assemblies to be tested. On each assembly, control circuits are used for testing additional control circuits embodied as interfaces comprising two control units, one of which is assigned to a system scan bus, and the other of which is assigned to an assembly scan bus. The two control units can mutually exchange the active control function so that one unit is active at a given time. In this way it is possible to address a control unit of an assembly via the system scan bus without affecting the assembly scan bus which is connected with the deactivated other control unit. This arrangement first permits the individual assemblies to be selected by means of their slot position address and only thereafter to test them in a test operation.