DS3800HADAGE
DS3800HADAGE
在幀中有消息頭和尾,數(shù)據(jù)報(bào)包到幀里。檢測錯(cuò)誤,調(diào)節(jié)數(shù)據(jù)流量。幀消息由源和目標(biāo)介質(zhì)訪問控制(media access control)MAC地址組成,并利用該信息和數(shù)據(jù)區(qū)的內(nèi)容建立CRC尾。數(shù)據(jù)鏈路層根據(jù)網(wǎng)絡(luò)采用拓?fù)湟?guī)則,發(fā)送幀,把幀發(fā)到物理層(網(wǎng)絡(luò)線纜)。網(wǎng)橋和交換器是數(shù)據(jù)鏈路層的設(shè)備。因?yàn)樗鼈兪侵С謳摹?/span>
單位是數(shù)據(jù)報(bào)(datagram)單位如網(wǎng)絡(luò)的IP數(shù)據(jù)報(bào)傳遞協(xié)議是網(wǎng)絡(luò)層功能的例子。這一術(shù)語物理層描述傳輸介質(zhì)、連接器和信號(hào)脈沖標(biāo)準(zhǔn)。中繼器或集線器(hub)也是物理層的設(shè)備,它與傳輸?shù)男畔木唧w內(nèi)容無關(guān)。幀是發(fā)送到介質(zhì)上的一組數(shù)字脈沖。用以傳輸信息。幀的大小為64-1518字節(jié)。幀包括預(yù)同步信號(hào),消息頭、數(shù)據(jù)信息和幀校驗(yàn)序列。中
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INDRAMAT BTV20.2EA-64B-33C-D-FW COMPUTER CONTROL*NIB*
NEW/REFURB REXROTH INDRAMAT HDS04.2-W200N-HS79-01-FW
One-day shipping available
INDRAMAT BTV20.2PA-64B-33C-D-FW COMPUTER CONTOLLER*RFB*
CLM-01.3-X-0-2-0-FW INDRAMAT
One-day shipping available
INDRAMAT CLC-V02.1C-FW USPP CLCV021CFW
INDRAMAT DDC01.2-N200A-DS50-00-FW USPP DDC012N200ADS500