Ezinsukwini ezimbalwa ezedlule kukhishwe izindaba zokuthi AbakwaFacebook bashicilele intuthuko ehlobene ne- ukudalwa kwe ibhodi le-PCIe, yini okufakiwe lukwenziwa kwewashi elincane le-athomu nesamukeli se-GNSS.
Ibhodi ekuqaleni lalakhiwe njengedivayisi e-modular, evumela ukusetshenziswa kwezinhlobonhlobo zama-chip atomic clock chips namamojula we-GNSS, afana ne-SA5X, mRO-50, SA.45s, ne-u-blox RCB-F9T. U-Orolia uhlose ukuqala ukukhiqizwa kwamabhodi aqediwe ngezincazelo ezilungiselelwe.
Ikhadi lesikhathi isakhiwa njengengxenye yephrojekthi yedivayisi yesikhathi yomhlaba ebanzi kuhloswe ngayo ukuhlinzeka ngezinto zokwenziwa kwamaseva wesikhathi esiyisisekelo (i-Time Master) (i-Open Time Server) engasetshenziswa kwingqalasizinda yakho futhi isetshenziswe, ngokwesibonelo, ukuhlela ukuvumelanisa kwesikhathi kuzikhungo zedatha.
Ukusebenzisa iseva ezimele kukuvumela ukuthi ungathembeli kumasevisi wenethiwekhi angaphandle ukuvumelanisa isikhathi esiqondile, nokuba khona kwewashi le-athomu elakhelwe ngaphakathi inikeza izinga eliphezulu lokuzimela uma kwenzeka ukwehluleka ekwamukelweni kwedatha evela kumasistimu esathelayithi (isib. ngenxa yezimo zezulu noma ukuhlaselwa).
Ubuciko besikhathi obususelwa ku-NTP busebenzisa iStratum 1, into ebalulekile exhunywe ngqo kumthombo wesikhathi onegunya, njengohlelo lokuzulazula lomhlaba jikelele lwesithelayithi (GNSS) noma iwashi le-cesium.
Isici kwephrojekthi ukuthi ukwakha iseva yesikhathi esiyinhloko, ungasebenzisa iseva ejwayelekile ngokususelwa ekwakhiweni kwe-x86, okubandakanya ikhadi lenethiwekhi elijwayelekile kanye nekhadi lesikhathi.
Kwiseva eshiwo, imininingwane yesikhathi esiqondile itholwa ivela kuma-satellite nge-GNSS futhi iwashi le-athomu lisebenza njenge-oscillator ezinze kakhulu, ivumela ukunemba okuphezulu kokugcinwa esimweni lapho kungekho lwazi olutholwa nge-GNSS. Ukuphambuka okungenzeka kusuka esikhathini esiqondile uma kwenzeka ukungakwazi ukuthola idatha nge-GNSS ebhodini elihlongozwayo kulinganiselwa ukuthi kungama-nanosecond angama-300 ngosuku.
Umshayeli we-ocp_pt ilungiselelwe i-Linux y kuhlelwe ukuthi kufakwe ku-Linux kernel 5.15.
Isilawuli isebenzisa i-PTP POSIX interface (/ dev / ptp2), i-GNSS nge-serial port / dev / ttyS7, iwashi le-athomu nge-serial port / dev / ttyS8 namadivayisi amabili i2c / dev / i2c- *, lapho amandla wewashi lehadiwe (i-PHC) angatholakala khona kumvelo yomsebenzisi.
Lapho uqala iseva ye-NTP (Network Time Protocol), kuphakanyiswa ukuthi kusetshenziswe i-Chrony ne-NTPd, futhi lapho kuqala iseva ye-PTP (Precision Time Protocol), kuphakanyiswa ukuthi kusetshenziswe i-ptp4u noma i-ptp4l ngokuhlangana nesitaki se-phc2sys ukunikeza ikhophi wamanani wesikhathi kusuka ewashini le-athomu kuya ekhadini lenethiwekhi.
Ukudidiyela kokusebenza komamukeli we-GNSS newashi le-athomu kungenziwa kukho kokubili i-hardware ne-software. Ukusebenza kwehardware kwemodyuli yokubhangqa kwenziwa ngesisekelo se-FPGA, futhi inguqulo yesoftware isebenza ezingeni lokuqapha okuqondile kwesimo somamukeli we-GNSS newashi le-athomu kusuka kuzinhlelo zokusebenza ezinjenge-ptp4l ne-chronyd.
Isizathu sokwakhiwa kwebhodi evulekile esikhundleni sokusebenzisa izixazululo ezilungele ukusetshenziswa ezitholakala emakethe, uhlobo lobunikazi bemikhiqizo enjalo, engasivumeli ukuthi siqinisekise ukuthi ukusetshenziswa kwayo kulungile, isoftware ehlongozwayo ayihambisani nezidingo zokuphepha. (Ezimweni eziningi, izinhlelo eziphelelwe yisikhathi ziyathunyelwa futhi ukulungisa ubungozi kungathatha izinyanga noma ngisho neminyaka ukuletha), kanye namandla amancane wokumisa nokuqapha (SNMP) (i-CLI yayo noma i-interface yomsebenzisi wewebhu inikezwa).
Ibhodi lingasetshenziselwa ukuhlela umsebenzi wamaseva wokuvumelanisa wesikhathi esihlukile. Imininingwane, izikimu, i-BOM, i-Gerber, i-PCB, namafayela we-CAD adingekayo ukwenza ibhodi kuthunyelwe ku-GitHub.
Umthombo: https://engineering.fb.com
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