Browse Prior Art Database

Functional Tester for Operator Panel

IP.com Disclosure Number: IPCOM000048104D
Original Publication Date: 1981-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 3 page(s) / 41K

Publishing Venue

IBM

Related People

Bigbie, SE: AUTHOR [+4]

Abstract

Described herein is a microprocessor control diagnostic functional tester for the operator panel of a matrix printer.

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Functional Tester for Operator Panel

Described herein is a microprocessor control diagnostic functional tester for the operator panel of a matrix printer.

Referring to the figure, the operator panel of a conventional matrix printer is shown above the dashed line and may consist of 12 switches arranged in a 4 x 3 matrix, three panel indicators labeled HEX LED, RDY LED and ATTN LED and associated circuitry including a debounce module, an AND gate and an encoder. These devices interface with the printer controller in a conventional manner.

The tester described herein and shown below the dashed line includes a microcomputer, appropriate interface circuitry and four test light-emitting diodes (LEDs), which are designated BBP (Begin Push Buttons), ENC ERR (Encoder Error), ERR (Error) and EOT (End of Test). Associated with the test is a test fixture comprised of pins which make contact with components of the operator panel circuit board and are wired to the tester circuits.

In operation, when the operator panel is placed in the pin fixture and the tester is powered up, power is automatically applied to the panel. Immediately all four test light indicators turn on. If any indicator does not turn on, the tester is not functional and the operator must take corrective action. Next, the microcomputer goes through a self diagnostic routine, checking itself and the interface circuitry of the tester. If any failure is detected, the four test indicator lights remain turned on and no further testing can be done. The operator will then have to take corrective action. If all tests are passed, the four test indicator lights turn off.

The microcomputer then goes through tests on the operator panel encoder for all meaningful combinations of input logic highs and lows, and monitors the outputs. Any failure will cause the Encoder Error test indicator to turn on, and no further testing can be done. If this test is passed, the Begin Push Button test indicator turns on. At this time, the operator must observe that the RDY LED and ATTN LED displays of...