TM 1–1520–238–T–3
14–4
14–2 SIGNAL NAME:
SYM GEN STATUS WORD TERMINAL FLAG
MEMORY LOCATION: 000675
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 14–11.
FAIL: Location of fault: if first digit displayed on HOD is 1, 3, 5, or 7, go to paragraph 14–3.
14–3 SIGNAL NAME:
SYM GEN STATUS WORD PROM FAIL
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
18
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
FAIL indicates a failed state of 256 words of programmable read only memory
(PROM) contained on memory cards A5 and A12.
REMARKS: From symbol generator to 1553 bus.
PASS:
If first digit displayed on HOD is 0, 1, 4, or 5, go to paragraph 14–4.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–4 SIGNAL NAME:
SYM GEN STATUS WORD PROCESSOR FAIL
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
17
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
FAIL indicates a failed state of processor card A11.
REMARKS: From symbol generator to 1553 bus.
PASS:
If first digit displayed on HOD is 0, 1, 2, or 3, go to paragraph 14–5.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
14–5 SIGNAL NAME:
SYM GEN STATUS WORD AUTO STBY
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
16
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Standby (STBY) indicates symbol generator has gone into standby due to no
valid message for 0.5 seconds.
REMARKS: From symbol generator to 1553 bus.
PASS:
If second digit displayed on HOD is 0, 2, 4, or 6, go to paragraph 14–6.
FAIL: Location of fault: replace FCC (TM 9–1230–476–20–1).
14–6 SIGNAL NAME:
SYM GEN STATUS WORD RAM FAIL
MEMORY LOCATION: 000675
MEMORY DATA BIT(S):
15
(BINARY)
CONDITION:
(None)
SIGNAL FUNCTION:
Indicates random access memory (RAM) status on A2, A3, and A4 cards.
REMARKS: From symbol generator to 1553 bus.
PASS:
If second digit displayed on HOD is 0, 1, 4, or 5, go to paragraph 14–7.
FAIL: Location of fault: replace symbol generator (TM 11–1520–238–23–2).
