Abstract: In order to test the functional and parametric characteristics of a unit without overloading a host computer, the host computer downloads a testing program to a plurality of digital signal processor modules which do all of the functional environmental emulation data generation and analysis of the data received from the unit under test. A reconfigurable application interface module is also programmed at the same time as the digital signal processor modules and is thus configured to accept basic emulation data generated by the digital signal processor modules and convert those data to the data environment that the unit under test is expected to experience in use. The application interface module also converts the data received from the unit under test into a format that the digital signal processor modules can analyze, the results of which analysis are made available to the host computer.

Abstract: On a printed circuit board or module card (20) of a standard size for a particular type of system, one or more different, smaller circuit cards or sub-modules (50) can be selectively mounted on the module card so as to utilize a maximum of its area. The module card has openings or holes (30) therein so as to provide component clearance and thus prevent the thickness of the module card from reducing the maximum permissible height of the components that can be mounted on the sub-modules. In order to minimize the amount of module card area devoted to interconnecting to the sub-modules, the sub-modules plug into the module card as the sub-module is moved in a direction perpendicular to the plane of the module card rather than in a direction parallel to the plane of the module card. Circuit wiring and switching (FIG.