Keysight 34401A, Руководство по обслуживанию

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Self-Test Procedures
Power-On Self-Test
Each time the multimeter is powered on, a small set of self-tests are
performed. These tests check that the minimum set of logic and
measurement hardware are functioning properly. The power-on
self-tests are listed below in the order they are executed. For a more
complete description of each test, see the description in the following
section, “Self-Test Descriptions” (see below).
•
Test 701, checks that the calibration security disable jumper is removed.
•
Self-test 624, determines the correct power-line frequency for the
measurement section.
•
Copy secured calibration constants from calibration ram
U505
to
working ram
U503
. Errors 740 through 748 may be reported during
this operation.
•
Self-test 625, establishes communication with the
I/O
processor
U700
.
•
Self-test 601, establishes communication with the front panel
U600
.
•
Self-test 603, checks that the
ADC
logic is functioning
U501
.
•
Self-test 604, checks that the
ADC
analog hardware is functioning.
•
Self-test 626, checks that
U700
passed its self-test.
Self-Test Descriptions
This section provides a brief description for each internal self-test
procedure including purpose, test setup, and failure criteria. Erroneous
self-test failures may occur when the power line voltage is improperly
set. Errors may also be produced by ac signals present on the
multimeter input terminals (front or rear) during self-test. Long test
leads can act as an antenna causing pick-up of ac signals.
Failing a self-test procedure indicates that parts of the multimeter are
not functioning properly and need to be serviced. Passing self-test gives
a better than 90% confidence that the Agilent 34401A hardware is
operational. However, passing self-test does not guarantee that the
multimeter will produce accurate results. Only performance verification
can ensure the accuracy of measurement results.
Chapter 6 Service
Self-Test Procedures
120