TM 1–1520–238–T–3
20–19
20–46 SIGNAL NAME:
DOP CROSSTRACK DEVIATION
MEMORY LOCATION: 000477
MEMORY DATA BIT(S):
7–4
(HEX)
CONDITION:
If first digit displayed on HOD is 0, and second digit is 0, 2, 4, or 6=0
If first digit displayed on HOD is 1, and second digit is 0, 2, 4, or 6=1
If first digit displayed on HOD is 2, and second digit is 0, 2, 4, or 6=2
If first digit displayed on HOD is 3, and second digit is 0. 2. 4, or 6=3
If first digit displayed on HOD is 4, and second digit is 0, 2, 4, or 6=4
If first digit displayed on HOD is 5, and second digit is 0, 2, 4, or 6=5
If first digit displayed on HOD is 6, and second digit is 0, 2, 4, or 6=6
If first digit displayed on HOD is 7, and second digit is 0, 2, 4, or 6=7
If first digit displayed on HOD is 0, and second digit is 1, 3, 5, or 7=8
If first digit displayed on HOD is 1, and second digit is 1, 3, 5, or 7=9
SIGNAL FUNCTION:
Indicates tenths field.
REMARKS: From Doppler through CPG MRTU Type III to FCC.
PASS:
Location of fault if CONDITION agrees with crosstrack deviation: CPG MRTU Type III, wiring
from CPG MRTU Type III to Doppler, Doppler. Troubleshoot wiring to isolate fault
(TM 9–1230–476–20–1).
FAIL: Location of fault: Doppler, wiring from Doppler to CPG MRTU Type III, CPG MRTU Type III.
Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
20–47 SIGNAL NAME:
DOP COSINE TRUE HEADING
MEMORY LOCATION: 000501
MEMORY DATA BIT(S):
18–17
(BINARY)
CONDITION:
If fifth digit displayed on HOD is 0 or 1=plus, north, west, up, to
If fifth digit displayed on HOD is 2 or 3=failure warning
If fifth digit displayed on HOD is 4 or 5=no computed data and no failure detected
If fifth digit displayed on HOD is 6 or 7=minus, south, east, down, from
SIGNAL FUNCTION:
Indicates sine/status of Doppler.
REMARKS: From Doppler through CPG MRTU Type III to FCC.
PASS:
If CONDITION agrees with heading, go to paragraph 20–48.
FAIL: Location of fault: Doppler, wiring from Doppler to CPG MRTU Type III, CPG MRTU Type III.
Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
20–48 SIGNAL NAME:
DOP COSINE TRUE HEADING
MEMORY LOCATION: 000501 AND 000502
MEMORY DATA BIT(S):
16–4 AND 19–18
(SCALAR)
CONDITION:
Monitor HOD; memory location response should indicate a positive from 0 to
180 degrees or a negative from 181 to 359 degrees.
SIGNAL FUNCTION:
Indicates Doppler cosine true heading.
REMARKS: From Doppler through CPG MRTU Type III to FCC.
PASS:
If CONDITION agrees with heading, go to paragraph 20–49.
FAIL: Location of fault: Doppler, wiring from Doppler to CPG MRTU Type III, CPG MRTU Type III.
Troubleshoot wiring to isolate fault (TM 11–1520–238–23–2).
