Install guide
ARMY TM 5-6675-308-34
MARINE CORPS TM 08837A-34/2
Table 4-14.1. IMU Testing, Alignment, and Troubleshooting Using Tape Reader, Part No. 877406-2 —
Continued
Malfunction
Test procedure
Normal indication
indication/corrective action
2s.
2t.
NOTE
A complete table of calibration pa-
rameters, including the cal data
checksum, will print during subtest
10. A failure table will print after
test 10 results, OK means the param-
eter was within tolerance; OOC
means the parameter was out of tol-
erance but has been recalibrated;
FAIL means the parameter was out
of tolerance and must be corrected
at the depot level.
At
end of test, TTY prints out:
ALIGNMENT COMPLETED
000000 000000
Press EXECUTE switch-indica- EXECUTE switch-indicator goes off
tor to off
Sequentially press PADS ON/ PADS ON/OFF switch-indicator
WHEN DONE TYPE:
RDY
ALIGNMENT HALTED:
Ensure IMU is oriented to 45 ±10
degrees to any cardinal heading and
azimuth is correct. Type RDY.
TTY will request a new measure-
ment of the last horizontal angle
followed by azimuth entry
TTY
prints out:
TYPE ONE OF: ACC REP, BYP
ALIGNMENT HALTED:
Type REP and repeat theodolite
test. If test fails a second time,
replace the porro prism assembly
TTY prints out:
THEODOLITE READING IN-
CONSISTANT
TYPE ONE OF: REP, BYP
Before using the theodolite readings
to calculate the porro prism cali-
bration constants, several feasabil-
ity
checks will be run on the read-
ings, If one or more readings were
in error, these checks will detect
an inconsistancy and give the op-
erator the option of repeating the
readings or bypassing the test. If
an inconsistency is detected for
three consecutive sets of readings,
the system will assume that PADS
is in error and will print out an
IMU failure. Return IMU to depot
if any lines 1020 thru 1025 indi-
cate a
failure. If only line 101 or
102
indicates a failure, replace the
porro prism assembly.
Return IMU to depot if following
test 9, TTY prints out:
NEED DEPOT CAL
OFF switch-indicator and EN-
goes off
TER switch
System shuts down
4-90.10
Change 5