Technical data

Self-test procedures are numbered in the order in which they are
executed. The order is designed to build confidence from a small kernel
towards progressively more complex internal configurations.
Many individual self-test procedures may be executed from the front
panel by selecting the desired test number from the parameter list of
the
TEST command (in the SYS MENU).
Note K101 is always open during self-test so that signals present on the
input terminals are disconnected. However, ac signals may still feed
through K101 causing self-test failures as mentioned earlier in this section.
601
Front panel does not respond The main
CPU U500 attempts to
establish serial communications with the front panel processor
U600.
During this test,
U600 turns on all display segments. Communication
must function in both directions for this test to pass.
602 RAM read/write failed This test writes and reads a 55
H
and AA
H
checker board pattern to each address of ram U503. Any incorrect
readback will cause a test failure. This error is only readable from the
remote interface.
603 A/D sync stuck The main
CPU issues an A/D sync pulse to U500-38
and to U501 where ADC slope counters are latched. A failure is detected
when a sync interrupt is not recognized and a subsequent time-out occurs.
604 A/D slope convergence failed The dc section is configured to the
measure zero state (
MZ) in the 10 V range. This test checks whether the
ADC integrator produces nominally the same number of positive and
negative slope decisions (
±10%) during a 20 ms interval.
605 Cannot calibrate rundown gain This test checks the nominal gain
between the integrating ADC and the U500 onchip ADC. This error is
reported if the procedure can not run to completion due to a hardware failure.
606 Rundown gain out of range This test checks the nominal gain
between the integrating
ADC and the U500 onchip ADC. The nominal
gain is checked to
±10% tolerance.
6
Chapter 6 Service
Self-Test Procedures
121