Functional Test

TM 11-7010-201-40-1/ET821-AA-MMI-010/E154 MTS/T O 31S5-2TSQ73-2-1

2-4. Functional Test. The functional test consists of a truth table verification of the Card Under Test (CUT). A truth

table for each type of IC in the system is stored in the control memory function (see figure 2-1). The control memory test

data (test pattern) is applied by the probe function to the CUT. Return data from the CUT is passed by the probe function

and applied to the error detect function. The error detect function compares the return data from the CUT with the truth

table (compare data),stored in data memory.

The appropriate FUNCTIONAL INPUT ERROR and FUNCTIONAL

OUTPUT ERROR indicators on the MTS front panel signify the results. The indicators (left to right) correspond to ICs

(top to bottom) of the CUT. The functional test is performed on one IC at a time, except for the 587117 card. On this

card, all ICs are tested at the same time. The mask and control memory functions, which control test length and any

special clocking, are enabled by the timing and control function. The mask data output disables all probe function output

gates except those related to the specific IC under test. The mask data is identified by a function of the card ID from

timing and control.

2-5. Test Sequence Completion.

Upon completion of the continuity and functional tests, the timing and control

function (see figure 2-1) returns the MTS to its original idle condition. The front panel GO or NO-GO indicator remains

lighted, depending on successful or unsuccessful completion of the tests. If a test sequence is to be repeated, either the

test set probe assembly is removed and reattached to the CUT, or the REPEAT CYCLE switch is pressed and released.

If continuous testing is required, the CONTINUOUS CYCLE switch is pressed and released. The CONTINUOUS CYCLE

indicator should be on for continuous operation and off for single-cycle operation.

2-6. Self-Test Operation. Self-test is started by attaching the test set probe assembly to terminal board TB101 (self-

test strip) located behind the access door on the front panel. A self-test card ID is generated by the probe function, and is

applied to the self-test function (see figure 2-1) through the probe function. The self-test function generates dummy card

ID signals corresponding to the card ID signals of the MTS testable system cards. One at a time, the dummy binary-

coded card IDs are applied to the data memory and mask functions. The MTS performs the card test sequence for each

card, with the self-test function supplying the test results. Each card ID test sequence is performed until all possible

function testing information is checked. If an error occurs, the MTS continues testing the same function on the dummy

card ID where the error is detected. To continue the self-test, the SELF-TEST switch on the front panel must be pressed

and released. If no error is detected, the MTS has passed the self-test and is in proper working condition. The MTS

requires approximately 7 seconds to complete the self-test sequence (without error).

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