TM 1–1520–238–T–3
14–5
14–7 SIGNAL NAME:
SYM GEN STATUS WORD RAM FAIL
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
14
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates RAM status on A12 card.
REMARKS: From symbol generator to 1553 bus.
PASS:
If second digit displayed on HOD is 0, 1, 2, or 3, go to paragraph 14–8.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–8 SIGNAL NAME:
SYM GEN STATUS WORD INTERNAL SYNC
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
12
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates either target acquisition designation sight (TADS) or pilot night vision
sensor (PNVS) forward looking infrared radar (FLIR) is not present.
REMARKS: From symbol generator to 1553 bus.
PASS:
If third digit displayed on HOD is 0, 1, 4, or 5, go to paragraph 14–9.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–9 SIGNAL NAME:
SYM GEN STATUS WORD PROCESSOR TIME OUT
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
11
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates state of time out flip–flop which is reset at beginning of each frame.
REMARKS: From symbol generator to 1553 bus.
PASS:
If third digit displayed on HOD is 0, 1, 2, or 3, go to paragraph 14–10.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–10 SIGNAL NAME:
SYM GEN STATUS WORD OVERVOLTAGE
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
10
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates when +5 VDC is exceeded.
REMARKS: From symbol generator to 1553 bus.
PASS:
If fourth digit displayed on HOD is 0, 2, 4, or 6, go to paragraph 14–11.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–11 SIGNAL NAME:
SYM GEN STATUS WORD TERMINAL FLAG
MEMORY LOCATION: 000732
MEMORY DATA BIT(S):
19
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
FAIL indicates a failed state of bits 12 through 18.
REMARKS: From symbol generator to 1553 bus.
PASS:
If first digit displayed on HOD is 0, 2, 4, or 6, go to paragraph 14–20.
FAIL: Location of fault: if first digit displayed on HOD is 1, 3, 5, or 7, go to paragraph 14–12.
