SNAP-PAC-R2 SNAP-PAC-R2
在總線兩端連接有端結(jié)器(或終端匹配器)，主要與總線進行阻抗匹配，限度吸收傳送端部的能量，避免信號反射回總線產(chǎn)生不必要的干擾。
總線結(jié)構(gòu)是使用同一媒體或電纜連接所有端用戶的一種方式，也就是說，連接端用戶的物理媒體由所有設(shè)備共享，各工作站地位平等，無中央結(jié)點控制，公用總線上的信息多以基帶形式串行傳遞，其傳遞方向總是從發(fā)送信息的結(jié)點開始向兩端擴散，如同廣播電臺發(fā)射的信息一樣，因此又稱廣播式計算機網(wǎng)絡(luò)。各結(jié)點在接受信息時都進行地址檢查，看是否與自己的工作站地址相符，相符則接收網(wǎng)上的信息。
使用這種結(jié)構(gòu)必須解決的一個問題是確保端用戶使用媒體發(fā)送數(shù)據(jù)時不能出現(xiàn)沖突。在點到點鏈路配置時，這是相當簡單的。如果這條鏈路是半雙工操作，只需使用很簡單的機制便可保證兩個端用戶輪流工作。在一點到多點方式中，對線路的訪問依靠控制端的探詢來確定。然而，在LAN環(huán)境下，由于所有數(shù)據(jù)站都是平等的，不能采取上述機制。對此，研究了一種在總線共享型網(wǎng)絡(luò)使用的媒體訪問方法：帶有碰撞檢測的載波偵聽多路訪問，英文縮寫成CSMA/CD。
這種結(jié)構(gòu)具有費用低、數(shù)據(jù)端用戶入網(wǎng)靈活、站點或某個端用戶失效不影響其它站點或端用戶通信的優(yōu)點。缺點是一次僅能一個端用戶發(fā)送數(shù)據(jù)，其它端用戶必須等待到獲得發(fā)送權(quán)；媒體訪問獲取機制較復(fù)雜；維護難，分支結(jié)點故障查找難。盡管有上述一些缺點，但由于布線要求簡單，擴充容易，端用戶失效、增刪不影響全網(wǎng)工作，所以是LAN技術(shù)中使用***普遍的一種。
全球瘋狂最低價
Opto 22 SNAP ethernet I/O with Analog, Input, and Output cards
Opto 22 SNAP-LCM4 SNAP Modular
OPTO 22 SNAP-LCM-4 USPP SNAPLCM4
OPTO 22 SNAP-LCSX-PLUS USPP SNAPLCSXPLUS
NEW OPTO 22 SNAP-PAC-S1
OPTO 22 SNAP-UP1-ADS USPP SNAPUP1ADS
OPTO 22 SNAP-LCSX USPP SNAPLCSX
OPTO22 SNAP-PAC-S1-FM NEW!
OPTO 22 SNAP-PAC-R2 NSFP SNAPPACR2
OPTO 22, SNAP-LCSX-PLUS SNAP; Controller
OPTO 22 SNAP-B3000-ENET NSFP SNAPB3000ENET
OPTO 22 SNAP-ENET-D64 NSFP SNAPENETD64
OPTO 22 SNAP-UP1-ADS ULTIMATE I/O PROCESSOR ***XLNT***
OPTO 22 Part SNAP-UP1-ADS Ultimate I/O Brain TCP/IP TRANSPORT 10Base T 100BaseTX
OPTO 22 SNAP-PAC-R2 USPP SNAPPACR2
OPTO 22 SNAP-ENET-D64 NSPP SNAPENETD64
Opto 22 Snap Ultimate I/O Unit, SNAP-UP1-ADS, WARRANTY
OPTO 22 SNAP-B3000-ENET USPP SNAPB3000ENET
OPTO 22 Part SNAP-B3000-ENET Ethernet I/O TCP/IP TRANSPORT 10BaseT 100BaseTX NEW
OPTO 22 SNAP IT ADS 30 DAY WARRANTY
NEW OPTO 22 SNAP-AIV-8 ANALOG INPUT MODULE 8 CHANNEL FOR SNAP PAC SYSTEM
OPTO 22 Part SNAP-B3000-ENET Ethernet I/O TCP/IP TRANSPORT 10Base T 100 Base TX
Opto 22 SNAP-B6 SNAP 32-channel Pamux Protocol Analog Brain Board
OPTO 22 SNAP-B3000-ENET Ethernet I/O Programmable Controller **XLNT**
Lot of 14 Opto 22 Snap I/O & 3 SNAPD6MC Board
OPTO 22 SNAP-ENET-D64 SNAP Ethernet I/O Brain - Digital Only
OPTO 22 SNAP-AIV-8 NSFP SNAPAIV8
OPTO 22 SNAP-B3000 NSFP SNAPB3000
OPTO 22 SNAP-ENET-S64 USPP SNAPENETS64
SNAP-IT-RM-UM16-GDDS OPTO22 SNAP-IT
OPTO 22 SNAP-SCM-485-422 Snap I/O Module
OPTO 22 SNAP-AIV-8 USPP SNAPAIV8
OPTO 22 SNAP-B3000 USPP SNAPB3000
OPTO 22 SNAP-SCM-485 USPP SNAPSCM485
11 OPTO22 SNAP I/O 4-CHANNEL DC INPUTS IDC5 -
OPTO 22 SNAP-BRS NSFP SNAPBRS
OPTO 22 SNAP-AIMA-I NSFP SNAPAIMAI
Opto 22 Snap Huge Lot
OPTO 22 Part SNAP-ENET-S64 Simple I/O TCP/IP TRANSPORT 10 Base T 100 Base TX
Opto 22 Simple I/O Ethernet Module SNAP-ENET-S64 - New in Box
Opto 22 SNAP AOD-29
OPTO 22 SNAP-BRS USPP SNAPBRS
OPTO 22 SNAP-SCM-232 USPP SNAPSCM232
NEW OPTO 22 SNAP-ENET-S64
NEW OPTO 22 SNAP-PS24
OPTO 22 SNAP B 3000 BRAIN & 4 CHANNEL DC INPUTS (LOT OF 8) SEE DETAILS
OPTO 22 SNAP-AIMA-I USPP SNAPAIMAI
Opto 22 SNAP-SCM-485 Communication Module with Protector Card and Cables, New !!
OPTO 22 SNAP-M64 USPP SNAPM64
NIB OPTO 22 SNAP-PS5-24DC TRANSFORMER 24 VDC INPUT 5VDC 4AOUTPUT SNAPPS524DC
Opto 22 SNAP ethernet I/O with Analog, Input, and Output cards
Opto 22 SNAP-LCM4 SNAP Modular
OPTO 22 SNAP-LCM-4 USPP SNAPLCM4
OPTO 22 SNAP-LCSX-PLUS USPP SNAPLCSXPLUS
NEW OPTO 22 SNAP-PAC-S1
OPTO 22 SNAP-UP1-ADS USPP SNAPUP1ADS
OPTO 22 SNAP-LCSX USPP SNAPLCSX
OPTO22 SNAP-PAC-S1-FM NEW!
OPTO 22 SNAP-PAC-R2 NSFP SNAPPACR2
OPTO 22, SNAP-LCSX-PLUS SNAP; Controller
OPTO 22 SNAP-B3000-ENET NSFP SNAPB3000ENET
OPTO 22 SNAP-ENET-D64 NSFP SNAPENETD64
OPTO 22 SNAP-UP1-ADS ULTIMATE I/O PROCESSOR ***XLNT***
OPTO 22 Part SNAP-UP1-ADS Ultimate I/O Brain TCP/IP TRANSPORT 10Base T 100BaseTX
OPTO 22 SNAP-PAC-R2 USPP SNAPPACR2
OPTO 22 SNAP-ENET-D64 NSPP SNAPENETD64
Opto 22 Snap Ultimate I/O Unit, SNAP-UP1-ADS, WARRANTY
OPTO 22 SNAP-B3000-ENET USPP SNAPB3000ENET
OPTO 22 Part SNAP-B3000-ENET Ethernet I/O TCP/IP TRANSPORT 10BaseT 100BaseTX NEW
OPTO 22 SNAP IT ADS 30 DAY WARRANTY
NEW OPTO 22 SNAP-AIV-8 ANALOG INPUT MODULE 8 CHANNEL FOR SNAP PAC SYSTEM
OPTO 22 Part SNAP-B3000-ENET Ethernet I/O TCP/IP TRANSPORT 10Base T 100 Base TX
Opto 22 SNAP-B6 SNAP 32-channel Pamux Protocol Analog Brain Board
OPTO 22 SNAP-B3000-ENET Ethernet I/O Programmable Controller **XLNT**
Lot of 14 Opto 22 Snap I/O & 3 SNAPD6MC Board
OPTO 22 SNAP-ENET-D64 SNAP Ethernet I/O Brain - Digital Only
OPTO 22 SNAP-AIV-8 NSFP SNAPAIV8
OPTO 22 SNAP-B3000 NSFP SNAPB3000
OPTO 22 SNAP-ENET-S64 USPP SNAPENETS64
SNAP-IT-RM-UM16-GDDS OPTO22 SNAP-IT
OPTO 22 SNAP-SCM-485-422 Snap I/O Module
OPTO 22 SNAP-AIV-8 USPP SNAPAIV8
OPTO 22 SNAP-B3000 USPP SNAPB3000
OPTO 22 SNAP-SCM-485 USPP SNAPSCM485
11 OPTO22 SNAP I/O 4-CHANNEL DC INPUTS IDC5 -
OPTO 22 SNAP-BRS NSFP SNAPBRS
OPTO 22 SNAP-AIMA-I NSFP SNAPAIMAI
Opto 22 Snap Huge Lot
OPTO 22 Part SNAP-ENET-S64 Simple I/O TCP/IP TRANSPORT 10 Base T 100 Base TX
Opto 22 Simple I/O Ethernet Module SNAP-ENET-S64 - New in Box
Opto 22 SNAP AOD-29
OPTO 22 SNAP-BRS USPP SNAPBRS
OPTO 22 SNAP-SCM-232 USPP SNAPSCM232
NEW OPTO 22 SNAP-ENET-S64
NEW OPTO 22 SNAP-PS24
OPTO 22 SNAP B 3000 BRAIN & 4 CHANNEL DC INPUTS (LOT OF 8) SEE DETAILS
OPTO 22 SNAP-AIMA-I USPP SNAPAIMAI
Opto 22 SNAP-SCM-485 Communication Module with Protector Card and Cables, New !!
OPTO 22 SNAP-M64 USPP SNAPM64
NIB OPTO 22 SNAP-PS5-24DC TRANSFORMER 24 VDC INPUT 5VDC 4AOUTPUT SNAPPS524DC
OPTO 22 SNAP-AIVRMS NSFP SNAPAIVRMS
OPTO 22 SNAP B4 DIGITAL BRAIN
OPTO 22 SNAP-ENET-64 SNAPENETS64 ETHERNET MODULE
OPTO 22 SNAP-PS24 NSFP SNAPPS24
OPTO 22 SNAP-PS5 NSFP SNAPPS5
Opto 22 SNAP-SCM-485-422 Serial Communications Module
OPTO 22 SNAP-B16MC NSFP SNAPB16MC
OPTO 22 SNAP-IDC5Q TWO AXIS QUADRATURE INPUT MOD *XLNT*
OPTO 22 SNAP-AOV-25 USPP SNAPAOV25
OPTO 22 SNAP-PS5 NSPP SNAPPS5
OPTO 22 SNAP-IDC5Q TWO AXIS QUADRATURE INPUT MOD *XLNT*
OPTO 22 SNAP-AIRTD USPP SNAPAIRTD
OPTO 22 SNAP-AIV NSFP SNAPAIV
OPTO 22 SNAP-B16MC NSPP SNAPB16MC
Opto 22 Snap B12M Rack Board, 3 Snap IAC5MA 4 Channel Modules, Snap B4M
SNAP-AIV OPTO 22 -10VDC TO +10VDC ANALOG INPUT MODULE
NEW SNAP-PAC-RCK16 OPTO 22 SNAPPACRCK16
OPTO 22 SNAP-PS5 USPP SNAPPS5
OPTO 22 SNAP-IDC5Q NSFP SNAPIDC5Q
OPTO 22 Part No. SNAP M64 16 Slot Module Rack / Base
OPTO 22 SNAP-B16M NSFP SNAPB16M
OPTO 22 SNAP-B16MC USPP SNAPB16MC
OPTO 22 OPTO,DIGITAL ONLY BRAIN SNAP-ENET-D64
OPTO 22 SNAP-AIV-72 NSFP SNAPAIV72
OPTO 22 SNAP-ENET-D64 SNAP Ethernet I/O Digital Brain
OPTO 22 SNAP-B16M USPP SNAPB16M
Opto 22 SNAP-B8MC
OPTO 22 SNAP ANALOG Part No. SNAP AIV 2 Channel Voltage Input
OPTO 22 SNAP-D64RS NSPP SNAPD64RS
NIB OPTO 22 SNAP-B8MC RACK 8POINT W/EXTRA TERMINAL BLOCK SNAPB8MC
OPTO-22 SNAP-M64 Snap I/O Rack New in the box! $100
OPTO22 SNAP I/O PBC6H *NEW*
Opto 22 SNAP-PS5-24DC Logic Power Supply
OPTO 22 SNAP-BRS
Lot Of 2 Opto 22 Snap Ultimate I/O Learning Center Control Units
SNAP-IT-RM-UM16 OPTO 22
OPTO 22 SNAP-D12MC NSFP SNAPD12MC
OPTO 22 SNAP-RACKDINB NSPP SNAPRACKDINB
Opto 22 SNAP Analog SNAP-AITM 2-Ch Type E, J, K Thermocouple Analog Input Module
Opto 22 SNAP SNAP-AIV 2-Ch -10VDC to +10VDC Analog Input Module
OPTO 22 SNAP I/O Rack B Series SNAP-M64 16 Module Rack NEW In Box
OPTO 22 SNAP-AOV-5 USPP SNAPAOV5
OPTO 22 SNAP-PAC-RCK12 USPP SNAPPACRCK12
Opto 22 SNAP-AIV 2 Channel Analog Module
Opto 22 SNAP-AIARMS 2 Channel Analog Input Module
Opto 22 SNAP-AOV-5 Analog Voltage Output Module 10VDC
OPTO 22 SNAP AIVRMS 2 Ch Analog Input 0-250 V RMS NEW
OPTO 22 SNAP-B3000-ENET Ethernet I/O Brain Analog/Digital/Serial, CE Mark, 5 VDC
OPTO 22 SNAP ANALOG Part No. SNAP AIVRMS 2 Channel Voltage Input 0 - 250 VOLTS
OPTO 22 SNAP-M16 NSPP SNAPM16
