The development of an automatic wiring analyser system for testing telephone switching rack backplanes

This paper describes the various stages in the evolution of a computer controlled automatic test system for checking the validity of the backplane wiring of very large electronic telephone exchange switching racks. Although the basic testing requirements are simply wiring continuity and insulation testing, the large physical size and the diversity of hardware to be tested in an essentially random sequence necessitated a very large and complex test system. The solutions to the difficult interface problems and those of handling are described, together with the approach taken to solve the complex software and programming problems, including those caused by the large volume of data to be handled.