 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] K. BENIKE          ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] VER/282-8451       ]      RELEASE NOTE( )        ] JULY 1987        ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] REL 19 AND SUBS               ]  CREW ( )  GROUND ( )  DUMP ONLY (X)]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC ( )  VU ( )  SM/PL ( )] 0, G1, G2, G3, G6, G8, G9, S2,  ]
 ]                                   ] S4, PL9                         ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: COMMFAULTS, FCOS, BCE                            ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: SBIO                                           ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] EFFECTS OF COMMFAULTS                                               ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:  * 25184                                               ]
 ] COMMFAULT STATUS IS SUPPLIED BY FCOS ON A TRANSACTION BASIS FOR     ]
 ] ALL BYPASSABLE INPUT TRANSACTIONS. TO DEMONSTRATE THE PROCESSING    ]
 ] WHICH LEADS TO THE GENERATION OF COMMFAULT STATUS CONSIDER AN EX-   ]
 ] AMPLE OF AN INPUT I/O TRANSACTION (SHOWN IN FIGURE 25074-1). THE    ]
 ] TRANSACTION UNDER CONSIDERATION IS A FICTITIOUS TRANSACTION BUT     ]
 ] TYPICAL OF BYPASSABLE TRANSACTIONS. INPUTS ARE REQUESTED ON ALL     ]
 ] EIGHT FC BUSES AND THE TRANSACTION CONTAINS 20 BCE ELEMENTS IN      ]
 ] EIGHT DIFFERENT BCE CHAINS.                                         ]
 ]                                                                     ]
 ] AT THE TIME THAT THE TRANSACTION IS INITIATED FCOS SETS THE         ]
 ] "TRANSIENT COMMFAULT" (BCE ELEMENT STATUS) FOR ALL BCE ELEMENTS     ]
 ] EQUAL TO THE "PERMANENT COMMFAULT" (BCE ELEMENT COMMFAULT),         ]
 ] THAT IS:                                                            ]
 ]                                                                     ]
 ] TRANS_CF_ST = PER_CF_ST                                             ]
 ]                                                                     ]
 ] ASSUMING THERE IS NO PERMANENT COMMFAULT THEN THE COMMFAULT         ]
 ] STATUS IS AS FOLLOWS:                                               ]
 ]                                                                     ]
 ] PERM_CF_ST = '000 000 000 000 00 00 00 00'                          ]
 ] TRANS_CF_ST = '000 000 000 000 00 00 00 00'                         ]
 ]                                                                     ]
 ] (NOTE:  BITS 1 THROUGH 20 CORRESPOND TO BCE ELEMENTS 1 THROUGH 20). ]
 ]                                                                     ]
 ] WHEN THE INPUT TRANSACTION COMPLETES, FCOS CHECKS FOR I/O ERRORS.   ]
 ] IF AN I/O ERROR HAS OCCURRED, FCOS DETERMINES WHICH BUSES HAD AN    ]
 ] ERROR AND FLAGS ALL THE BCE ELEMENTS ON THESE BUSES AS "COMMFAULT-  ]
 ] ED". FOR EXAMPLE IF FC1 HAD AN ERROR THEN THE TRANSIENT COMMFAULT   ]
 ] STATUS WOULD BE SET TO:                                             ]
 ]                                                                     ]
 ] TRANS_CF_ST = '111 000 000 000 00 00 00 00'                         ]
 ]_____________________________________________________________________]
 @




 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] K. BENIKE          ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] VER/282-8451       ]      RELEASE NOTE ( )       ] JULY 1987        ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ] EFFECTS OF COMMFAULTS                                               ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] NOTE THAT ON THE FIRST I/O ERROR NO PROCESSING IS PERFORMED TO      ]
 ] DETERMINE WHICH OF THE THREE ELEMENTS ON THE BUS, (ELM1, ELM2,      ]
 ] ELM3) HAD AN ERROR.                                                 ]
 ]                                                                     ]
 ] SUPPOSE THE TRANSACTION IS INITIATED AGAIN AND AN I/O ERROR         ]
 ] OCCURS ON THE SAME BUS. THE SECOND I/O ERROR ON THIS TRANSACTION    ]
 ] CAUSES FCOS TO DETERMINE WHICH BCE ELEMENTS (ONE PER BUS) HAD THE   ]
 ] ERROR. SUPPOSE THE ERROR IS DETERMINED TO HAVE OCCURRED ON ELM1,    ]
 ] THEN ELM1 IS "BYPASSED" BY NO-OPING OF THE COMMAND WORD. THE        ]
 ] PERMANENT COMMFAULT FOR ELM1 IS ALSO SET.                           ]
 ]                                                                     ]
 ] PERM_CF_ST = '100 000 000 000 00 00 00 00'                          ]
 ]                                                                     ]
 ] THE TRANSIENT COMMFAULT IS SET AS BEFORE TO INDICATE COMMFAULT ON   ]
 ] BCE ELEMENTS, ELM1, ELM2, AND ELM3. IF ELM1 WAS THE ONLY SOURCE     ]
 ] OF THE I/O ERROR THEN NO FURTHER ERRORS WILL OCCUR BECAUSE THE      ]
 ] COMMAND CORRESPONDING TO ELM1 IS NO LONGER EXECUTED. IF ELM2 OR     ]
 ] ELM3 WERE ALSO EXPERIENCING ERRORS THEN THEY WILL BE BYPASSED ONE   ]
 ] BY ONE AS THE ERRORS ARE DETECTED ON EACH SUBSEQUENT PASS UNTIL     ]
 ] THERE ARE NO ERRORS LEFT IN THE CHAIN. ON THE OTHER HAND, IF ON     ]
 ] THE SECOND PASS ERRORS OCCUR ON BUSES (BCE CHAINS) OTHER THAN       ]
 ] BUS FC1, THEN THE FIRST ELEMENT EXPERIENCING AN ERROR IN EACH       ]
 ] CHAIN (THAT HAS AN ERROR) WILL BE BYPASSED. FOR EXAMPLE, IF ELM4    ]
 ] ON FC2 EXPERIENCED AN ERROR ON THE SECOND PASS THEN IT WILL BE      ]
 ] BYPASSED. IT SHOULD BE NOTED THAT WHEN ERRORS OCCUR ON CONSECUTIVE  ]
 ] PASSES, IT IS POSSIBLE TO HAVE BCE ELEMENTS BYPASSED THAT ONLY      ]
 ] EXPERIENCED ONE ERROR.                                              ]
 ]                                                                     ]
 ] THE BYPASS PROCESS IS USED TO AVOID COMMFAULTING ALL THE DATA RE-   ]
 ] CEIVED ON A BUS WHEN ONLY ONE BCE ELEMENT IS CAUSING THE ERROR.     ]
 ] THIS IS PARTICULARLY IMPORTANT WHERE "SERIAL DEVICES", SUCH AS      ]
 ] THE IMU'S, ARE IN THE BCE CHAIN. SERIAL DEVICES CAUSE I/O ERRORS    ]
 ] WHEN POWERED OFF BECAUSE THEY FAIL TO RETURN RESPONSE DATA. THESE   ]
 ] ELEMENTS MUST THEREFORE BE BYPASSED TO AVOID COMMFAULT OF OTHER     ]
 ] DATA IN THAT BCE CHAIN.                                             ]
 ]_____________________________________________________________________]
 @




 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] K. BENIKE          ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] VER/282-8451       ]      RELEASE NOTE ( )       ] JULY 1987        ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ] EFFECTS OF COMMFAULTS                                               ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] APPLICATION PROCESSING NORMALLY USES THE QUANTITY CALLED            ]
 ] "TRANSIENT COMMFAULT" WHEN DETERMINING THE DATA WHICH CAN BE        ]
 ] USED IN THE RS WITHOUT EXPOSURE TO DIVERGENCE AND POTENTIAL FAIL-   ]
 ] TO-SYNC. THE TRANSIENT COMMFAULT STATUS DOES NOT INDICATE PERMANENT ]
 ] LOSS OF COMMUNICATION WITH ANY DEVICE. IN FACT SINCE ALL ELEMENTS   ]
 ] OF A BCE CHAIN ARE COMMFAULTED FOR ANY ERROR IN THE CHAIN IT IS     ]
 ] VERY LIKELY THAT A TRANSIENT COMMFAULT WILL OCCUR FOR DATA RESIDING ]
 ] IN A CHAIN CONTAINING A SERIAL DEVICE SUCH AS THE IMU'S, MSBLS,     ]
 ] STAR TRACKER, OR KU-BAND RADAR IF THESE DEVICES ARE POWERED OFF OR  ]
 ] NOT EVEN CONNECTED TO THE BUS.                                      ]
 ]                                                                     ]
 ] AN EXAMPLE WHERE THE USE OF THE TRANSIENT COMMFAULT CAN BE A        ]
 ] PROBLEM IS ILLUSTRATED IN DR 25074. THE FSW HAS SPECIFIC RE-        ]
 ] QUIREMENTS TO ANNUNCIATE CERTAIN DEDICATED DISPLAY SINGLE CONTACT   ]
 ] SWITCHES AS INVALID (I.E., SWITCH IS NOW CONSIDERED IN SPECIFIED    ]
 ] DEFAULT POSITION) ON THE OCCURRENCE OF A COMMFAULT. IN THE EXAMPLE  ]
 ] GIVEN IN THE DR, AN IMU DISCRETE INPUT TRANSACTION WAS FAILED. THIS ]
 ] DISCRETE IS IN THE SAME INPUT TRANSACTION AS SOME OF THE DEDICATED  ]
 ] DISPLAY SINGLE CONTACT SWITCHES. CONSEQUENTLY THE ERROR MESSAGE     ]
 ] WOULD BE ANNUNCIATED AS INVALID (DEFAULTED) SWITCH INPUTS. IN FACT, ]
 ] THE MESSAGE ONLY REFLECTS THAT THE ERROR OCCURRED ON THE TRANS-     ]
 ] ACTION AND DOES NOT NECESSARILY REFLECT A SWITCH FAILURE. THE       ]
 ] SPECIFIC DEDICATED DISPLAY SWITCHES AND THE ERROR MESSAGES ARE      ]
 ] IDENTIFIED IN THE LIST BELOW VIA THEIR MML NUMBER AND THE ERROR     ]
 ] MESSAGE.                                                            ]
 ]                                                                     ]
 ]        MML  NO.                   MESSAGE                           ]
 ]        --------                   -------                           ]
 ]                                                                     ]
 ]        V94X4762X                DISPLAY SW R                        ]
 ]                                                                     ]
 ]        V94X4763X                DISPLAY SW A                        ]
 ]                                                                     ]
 ]        V94X4761X                DISPLAY SW L                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @




 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] K. BENIKE          ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] VER/282-8451       ]      RELEASE NOTE ( )       ] JULY 1987        ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ] EFFECTS OF COMMFAULTS                                               ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]        MML  NO.                DOWNLIST PARAMETER                   ]
 ]        -------                 ------------------                   ]
 ]        V96X2255X               RHADI ERROR SWITCH INVALID           ]
 ]        V96X2251X               RHADI RATE SWITCH INVALID            ]
 ]        V90X7179X               RHADI ATT SELECT INVALID             ]
 ]        V96X2275X               RAIR DATA SWITCH INVALID             ]
 ]        V96X2213X               RHHSI MODE SWITCH INVALID            ]
 ]        V96X2215X               RHHSI SOURCE SWITCH INVALID          ]
 ]        V96X2217X               RHHSI TRANS SWITCH INVALID           ]
 ]        V96X2295X               RH RADAR ALT SWITCH INVALID          ]
 ]                                                                     ]
 ]        V90X7776X               AFT ADI ERROR SWITCH INVALID         ]
 ]        V90X7777X               AFT ADI RATE SWITCH INVALID          ]
 ]        V90X7775X               AFT ADI ATT SWITCH INVALID           ]
 ]                                                                     ]
 ]        V96X2155X               LH ADI ERROR SWITCH INVALID          ]
 ]        V96X2151X               LH ADI RATE SWITCH INVALID           ]
 ]        V90X7178X               LH ADI ATT SELECT SW INVALID         ]
 ]        V96X2175X               LH AIR DATA SWITCH INVALID           ]
 ]        V96X2113X               LH HSI MODE SWITCH INVALID           ]
 ]        V96X2115X               LH HSI SOURCE SWITCH INVALID         ]
 ]        V96X2117X               LH HSI TRANS SWITCH INVALID          ]
 ]        V96X2195X               LH RADAR ALT SWITCH INVALID          ]
 ]                                                                     ]
 ] ANOTHER CASE WHERE UNEXPECTED FAILURE MESSAGES CAN BE GENERATED     ]
 ] AS A RESULT OF FCOS PROCESSING OF COMMFAULTS IS DESCRIBED BY        ]
 ] DR 25184. HERE, BECAUSE ALL EIU'S ARE ON THE SAME TRANSACTION,      ]
 ] A COMMFAULT ON EIU 3 EVENTUALLY RESULTS IN AN ME1 PAD DATA PATH     ]
 ] FAIL HOLD. FCOS COMMFAULTS THE ENTIRE TRANSACTION FOR TWO 40 MSEC   ]
 ] CYCLES CAUSING THE SSME SOP TO SET DATA PATH FAIL MESSAGES FOR      ]
 ] ME1, ME2, AND ME3. THE LAUNCH SEQUENCER CHECKS THESE FLAGS          ]
 ] SEQUENTIALLY (IN ORDER ME1, ME2, AND ME3) AND WILL, PER REQUIRE-    ]
 ] MENTS, GENERATE THE PAD DATA PATH FAIL HOLD FOR THE FIRST ME DATA   ]
 ] PATH FAIL FLAG DETECTED "ON" AND NOT CHECK THE REMAINING FLAGS.     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @







 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] K. BENIKE          ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] VER/282-8451       ]      RELEASE NOTE ( )       ] JULY 1987        ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ] EFFECTS OF COMMFAULTS                                               ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ] NONE, EXCEPT FOR DR 25074 AND DR 25184 WHICH FOLLOWS:               ]
 ]                                                                     ]
 ]  WHEN A SWITCH DEFAULT MESSAGE APPEARS ON THE MESSAGE LINE, THREE   ]
 ]  THINGS COULD HAVE HAPPENED:                                        ]
 ]                                                                     ]
 ]  A.   A TEMPORARY COMMFAULT                                         ]
 ]  B.   AN INDIVIDUAL SWITCH FAILURE                                  ]
 ]  C.   A PERMANENT COMMFAULT (BYPASS)                                ]
 ]                                                                     ]
 ]  CASE C CAN BE ISOLATED BY EXAMINING THE FAULT SUMM PAGE TO SEE     ]
 ]  IF ANY OF THE FOLLOWING MESSAGES ARE PRESENT:                      ]
 ]                                                                     ]
 ]   BCE STRG 1 A                                I/O ERROR FF1         ]
 ]   BCE STRG 2 A            OR                  I/O ERROR FF2         ]
 ]   BCE STRG 3 A                                I/O ERROR FF3         ]
 ]                                                                     ]
 ]  IF SO, THE SWITCHES CORRESPONDING TO THE BYPASSED BCE ELEMENT      ]
 ]  ARE DEFAULTED (I.E., LH SWITCHES FOR FF1, RH SWITCH FOR FF2 OR     ]
 ]  AFT SWITCHES FOR FF3).                                             ]
 ]                                                                     ]
 ]  ON THE OTHER HAND, IF SOME OTHER "FF MDM BYPASS" MESSAGE IS        ]
 ]  PRESENT ON THE FAULT SUMM PAGE THEN IN ALL LIKELIHOOD THIS         ]
 ]  BYPASS WAS THE CAUSE OF THE TEMPORARY COMMFAULT (CASE A) FOR       ]
 ]  THE SWITCHES AND ALL THE SWITCHES ARE FUNCTIONING PROPERLY.        ]
 ]                                                                     ]
 ]  IF THE FAULT SUMM PAGE HAS NO BYPASS INDICATIONS THEN GROUND       ]
 ]  SUPPORT WILL BE NECESSARY TO RESOLVE BETWEEN CASE A (TEMPORARY     ]
 ]  COMMFAULT) AND CASE B (ACTUAL SWITCH FAILURE). THE GROUND RE-      ]
 ]  CEIVES THE INDIVIDUAL SWITCH INVALID INDICATORS ON TELEMETRY       ]
 ]  (SEE ABOVE). IF NONE OF THESE ARE SET THEN A TEMPORARY COMMFAULT   ]
 ]  (CASE A) HAS OCCURRED AND ALL THE SWITCHES ARE STILL FUNCTIONING   ]
 ]  PROPERLY.                                                          ]
 ]                                                                     ]
 ]  FOR OTHER SIMILAR CASES, SUCH AS DR 25184, BE AWARE THAT TEMPORARY ]
 ]  COMMFAULT PROCESSING MAY BE RESPONSIBLE FOR "APPARENT FAILURE"     ]
 ]  ANNUNCIATION MESSAGES WHICH ARE DIFFERENT FROM THE ACTUAL          ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @










 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ]                    ]    PASS PROGRAM NOTE        ]     25074    *   ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ]                    ]      RELEASE NOTE ( )       ]                  ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]        EFFECTS OF COMMFAULTS                                        ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ] FAILURE (LRU 1 INSTEAD OF LRU3, ETC.).                              ]
 ]                                                                     ]
 ]   FC 1     FC 2     FC 3     FC 4     FC 5    FC 6    FC 7    FC 8  ]
 ]  (FF 1)   (FF 2)   (FF 3)   (FF 4)   (FA1)   (FA2)   (FA3)   (FA4)  ]
 ] ------------------------------------------------------------------- ]
 ] ]       ]        ]        ]        ]       ]       ]       ]      ] ]
 ] ] ELM1  ]  ELM4  ]  ELM7  ] ELM10  ]       ]       ]       ]      ] ]
 ] ]       ]        ]        ]        ]       ]       ]       ]      ] ]
 ] ]-------]--------]--------]--------]       ]       ]       ]      ] ]
 ] ]       ]        ]        ]        ] ELM13 ] ELM15 ] ELM17 ] ELM19] ]
 ] ] ELM2  ]  ELM5  ]  ELM8  ] ELM11  ]       ]       ]       ]      ] ]
 ] ]       ]        ]        ]        ]-------]-------]-------]------] ]
 ] ]-------]--------]--------]--------]       ]       ]       ]      ] ]
 ] ]       ]        ]        ]        ] ELM14 ] ELM16 ] ELM18 ] ELM20] ]
 ] ] ELM3  ]  ELM6  ]  ELM9  ] ELM12  ]       ]       ]       ]      ] ]
 ] ]       ]        ]        ]        ]       ]       ]       ]      ] ]
 ] ]----------------------------------]------------------------------] ]
 ] ]                                  ]                              ] ]
 ] ] A BCE CHAIN OF 3 BCE ELEMENTS.   ] A BCE CHAIN OF 2 ELEMENTS    ] ]
 ]                                                                     ]
 ] DEFINITIONS:                                                        ]
 ] 1.   BCE ELEMENT - AN ELEMENT OF A I/O TRANSACTION CHARACTERIZED    ]
 ]      BY A SET OF BCE INSTRUCTIONS.                                  ]
 ] 2.   BCE ELEMENT BYPASS - THE PROCESS OF NO-OPING A BCE ELEMENT.    ]
 ] 3.   BCE CHAIN - A SEQUENCE OF BCE ELEMENTS ON THE SAME BUS.        ]
 ]                                                                     ]
 ]       FIGURE 25074-1 TYPICAL GNC FC INPUT I/O TRANSACTION.          ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE: 8/4/88 ]                             ]
 ]    ____________________       ________]                             ]
 ]PF MGR:  SAM ANKNEY       DATE: 8/10/88]                             ]
 ]       _________________       ________] JACK BOYKIN         8/17/88 ]
 ]SSD: MICHAEL BRIEDEN      DATE: 8/8/88 ]___________________ ________ ]
 ]    ____________________       ________] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @
