MULTIPLEX READ CODE INTERPRETATIONS

TM 1–1520–238–T–3 5–2 Change 5 Personnel Required: (2) References: TM 1–1270–476–T TM 1–1520–238–T–6 TM 1–5855–265–T TM 9–1090–208–23–2 TM 9–1230–476–20–2 TM 9–1270–221–23 Equipment Conditions: Ref Condition TM 9–1090–208–23–2 GUN AND CONTROL SUBSYSTEM – MAINTENANCE OPERATIONAL CHECK in progress NOTE �All multiplex read code responses are read from right to left. �Multiplex read codes must be used in conjunction with applicable Maintenance Operational Check (MOC) in progress. �Multiplex read codes are observed on the HOD (ADC) or CDU (ADD). MULTIPLEX READ CODE INTERPRETATIONS 5–1 SIGNAL NAME: PLT SAFE/ARM SW MEMORY LOCATION: 001120 MEMORY DATA BIT(S): 12–13 (BINARY) CONDITION: If the third digit displayed on heads out display (HOD) is 0 or 4=OFF If the third digit displayed on HOD is 2 or 6=SAFE If the third digit displayed on HOD is 3 or 7=ARM SIGNAL FUNCTION: Selects weapon system status. REMARKS: From pilot fire control panel (FCP) through left–hand (LH) forward avionics bay (FAB) multiplex remote terminal unit (MRTU) Type I to fire control computer (FCC). PASS: If CONDITION displayed on HOD corresponds to the setting of pilot FCP SAFE/ARM switch, go to paragraph 5–2. FAIL: Location of fault: pilot FCP, wiring from pilot FCP to LH FAB MRTU Type I, LH FAB MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1230–476–20–2). 5–2 SIGNAL NAME: CPG SAFE/ARM SW MEMORY LOCATION: 001075 MEMORY DATA BIT(S): 12–13 (BINARY) CONDITION: If the third digit displayed on HOD is 0 or 4=OFF If the third digit displayed on HOD is 2 or 6=SAFE If the third digit displayed on HOD is 3 or 7=ARM SIGNAL FUNCTION: Selects weapon system status. REMARKS: From copilot/gunner (CPG) fire control panel (FCP) through CPG MRTU Type III to FCC. PASS: If CONDITION displayed on HOD corresponds to the setting of CPG FCP SAFE/ARM switch, go to paragraph 5–3. FAIL: Location of fault: CPG FCP, wiring from CPG FCP to LH FAB MRTU Type I, LH FAB MRTU Type I. Troubleshoot wiring to isolate fault (TM 9–1230–476–20–2).