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Fluke 900 User Manual

Page 39

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FLUKE 900 SERVICE MANUAL

Selftest

/SHORT is checked to see if the line is hi^ (ie. not shorted to ground). /SYNCEN and
/RELEN are tested by having sync latches or relays cause a fault and verifying that the fault
occurred.

Four bytes of test results are presented:

BYTE 0

b7 thru 5-0 (not used)
b4 -/STRFRQ output ofTC PAL not woiking
b3 - Interrupts failed
b2 - /SYNCEN line test failed
bl - /SHORT test failed
bO - /RELEN test failed
NOTE: only interrupts generated by TIME port are tested.

BYTE 1

b7 thru 3 - 0 ( not used )
b2 - test time timer
bl -10 ms timer
bO -1 ms timer

Each bit in bytes 2 and 3 corresponds to one execution of the test cycle, set up to produce the
expected results. If any bit in bytes 2 or 3 is set it means that results were not as expected. For
example, if b6 in byte 2 is set it means that the gate function was observed to be not active or
faults were detected. Trigger is programmed with one word Gevel) in byte 2 trigger test; for
byte 3, trigger is programmed with two words (edge). For aU W2 related tests (byte 3 bits 3
thru 0), W1 always occurs.

BYTE 2

b7 - gate did not occur no faults
b6 - gate occurred no faults
b5 - gate did not occur, fatilts
b4 - gate occurred, faults
b3 - trigger did not occur, no faults
b2 - trigger occurred, no fault
bl - trigger did not occur, faults
bO - trigger occurred, faults

BYTE 3

b7 - trigger W1 did not occur, no faults
b6 - trigger W1 occurred, no faults
b5 - trigger W1 did not occur, faults
b4 - trigger W1 occurred, faults
b3 - trigger W2 did not occur, no faults
b2 - trigger W2 occurred, no faults
bl - trigger W2 did not occur, faults

bO - trigger W2 occurred, faults

3 - 1 5