GB1328978A - Electronic unit testing systems - Google Patents

Abstract

1328978 Digital computers; testing components PLESSEY CO Ltd 16 June 1971 [17 June 1970] 29495/70 Heading G4A [Also in Division G1] A test unit EUT for electrical circuits (e.g. parts of a computer) has a plug attachment UUT for connection to the circuit and is connected to a digital computer COMP holding diagnostic program routines which the unit EUT executes. Apparatus.-The computer may be one computer of a number in a system and has a magnetic tape store MTS holding diagnostic programs and a teleprinter TP for printing out results. The test unit has a control panel CONTPAN (Fig. 2, not shown) having keys by which an operator controls the running of the diagnostic programs and having lights and numeral indicators which indicate the progress of the program. The computer sends a transfer word via 1/O CHAN and circuit RXC to decode R & FCC which distributes other decoded signals within the unit EUT. A matrix RCM of mercury wetted reed relays, addressed by circuit RCAC, can be selectively activated to connect circuits under test to measuring circuits (e.g. digital voltmeter DVM, variable voltage supply VVS and strobe generator SG) stimulus circuits SC which effect the tests, and the output register O/P REG, which feeds COMP with the results of the tests. The tests may be for open circuit, short circuit, resistance values, catastrophic and degraded failures, &c. The plug attachment UUT has a polarizing device which identifies the circuit being tested and prevents a unit being plugged into the wrong position. Operation.-(Fig. 3, not shown). The unit to be tested is plugged in, the computer tests the link between the test unit and itself using a looptest routine, then tests the circuits in the test unit, then tests the unit to be tested. Up to six units may be tested sequentially.