 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ]  J.W. MAGLEY       ]    PASS PROGRAM NOTE        ]     58769        ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  10/31/85  ]
 ]  IBM/282-8939      ]      RELEASE NOTE( )        ] REV A: 10/24/89  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ]   OI5 AND SUBS                ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )]   G1, G2, G3, G6, G8            ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: IMU, RM                                          ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.72                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]        POSSIBLE PREMATURE IMU DILEMMA ANNUNCIATION                  ]
 ]_____________________________________________________________________]
 ] DESCRIPTION: IT IS POSSIBLE FOR IMU RM PROCESSING TO INITATE 2-LEVEL]
 ] PROCESSING WITH A NON-ZERO DILEMMA COUNTER VALUE, WHICH COULD LEAD  ]
 ] TO A PREMATURE IMU DILEMMA ANNUNCIATION.  THIS CAN OCCUR UNDER THE  ]
 ] FOLLOWING CONDITIONS:                                               ]
 ]                                                                     ]
 ]  1) GOING FROM 2-LEVEL TO 3-LEVEL DUE TO CREW RESELECTION, THE      ]
 ]     DILEMMA COUNTER CAN STILL BE INCREMENTED (0 TO 1) BEFORE THE    ]
 ]     THIRD IMU IS ACCEPTED FOR SELECTION FILTER.                     ]
 ]  2) GOING FROM 2-LEVEL TO 3-LEVEL WITH A NON-ZERO DILEMMA COUNTER   ]
 ]     FOLLOWING CLEARANCE OF A COMMFAULT.                             ]
 ]  3) GOING FROM 2-LEVEL TO 1-LEVEL OR 0-LEVEL WITH A NON-ZERO DILEMMA]
 ]     COUNTER (AND THEN RETURNING TO 2-LEVEL FOLLOWING COMMFAULT      ]
 ]     CLEARANCE).                                                     ]
 ]                                                                     ]
 ] IN EACH OF THESE CASES THE DILEMMA COUNTER IS NOT RESET ON LEAVING  ]
 ] 2-LEVEL PROCESSING.  IF A MISCOMPARE CONDITION EXISTS ON REENTERING ]
 ] THE 2-LEVEL, POSSIBLY UNRELATED TO THE ORIGINAL CONDITION, THEN THE ]
 ] DILEMMA COUNTER WILL BEGIN INCREMENTING FROM THE PREVIOUS NON-ZERO  ]
 ] VALUE.  THE DILEMMA MESSAGE COULD THEN BE ANNUNCIATED BEFORE THE    ]
 ] INTENDED NUMBER OF PASSES HAD BEEN COMPLETED.                       ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ] BE AWARE THAT THE IMU DILEMMA MESSAGE MAY BE ANNUNCIATED PREMATURELY]
 ] AND/OR ERRONEOUSLY WHEN IMU RM REENTERS 2-LEVEL PROCESSING.         ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 11/30/89]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: SAM ANKNEY           DATE 11/30/89]                             ]
 ]    --------------------      ---------]M.C. GREMILLION     12/07/89 ]
 ]PF MGR:MOISES N. MONTEZ   DATE 12/06/89]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @
 DR58926
