 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] D. MENG            ]    PASS PROGRAM NOTE        ]         35211 *  ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  AUG. 1987 ]
 ] SSOAS/(281)335-2226]      RELEASE NOTE( )        ] REV B: 04/09/97  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI-26B AND SUBS               ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC ( )  VU ( )  SM/PL ( )]   G1, G3, G6                    ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: KEYBOARD, BUS, I/O                               ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: SBIO                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] I/O RESET WITH FAILED MTU OR GPS CAUSES BFS TO DOWNMODE A STRING    ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:   * REFERENCE DR063682, BO5284                         ]
 ]                                                                     ]
 ] WHEN AN I/O RESET IS ENTERED IN THE PASS GNC SYSTEM WITH AN MTU     ]
 ] ACCUMULATOR OR GPS RECEIVER FAILED, THE MTU/GPS ELEMENT WILL        ]
 ] BE BYPASSED AFTER "N" ERRORS (N>2).  THIS IS DUE TO ALL TRANSACTION ]
 ] COUNTERS BEING RESET FOR EACH OF THE SEVEN BUS/STRINGS RESTORED     ]
 ] (ONE PER MAJOR CYCLE). SINCE MTU/GPS I/O IS PERFORMED ONCE PER      ]
 ] MAJOR CYCLE, ITS COUNTER IS INCREMENTED AND CLEARED UNTIL ALL       ]
 ] RESTORES ARE COMPLETE. THE ERROR COUNT THEN REACHES TWO.  THE BFS   ]
 ] BYPASSES THE MTU/GPS AFTER TWO ERRORS AND, BECAUSE PASS HAS NOT YET ]
 ] BYPASSED THE MTU/GPS (DUE TO COUNTERS BEING CLEARED), THE BFS       ]
 ] DOWNMODES THE APPROPRIATE STRING.                                   ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ] IF AFTER ENTERING "I/O RESET EXEC" IN THE PASS SYSTEM WITH AN MTU   ]
 ] ACCUMULATOR OR GPS RECEIVER FAILED AND A MESSAGE APPEARS ON THE BFS ]
 ] DISPLAY STATING THAT A STRING WAS DOWNMODED, PERFORM AN I/O RESET   ]
 ] IN BFS AFTER THE PASS I/O RESET IS COMPLETE (WAIT FOR 10 SECONDS TO ]
 ] ELAPSE).                                                            ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]SSOAS:   JOHN MAGLEY      DATE 04/17/97]                             ]
 ]      ------------------      ---------]                             ]
 ]ASD:    ERIC C. BINGHAM   DATE 04/17/97]                             ]
 ]      ------------------      ---------] MELVIN R. ROTHER   06/06/97 ]
 ]PF MGR:  KAYLENE KINDT    DATE 04/16/97]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @
