基于总线的多机通信系统设计样本.doc

摘要在多机通信领域．由于单片机具备灵活高效多机通信功能和价格优势，应用越来越广泛，但由于单片机收发信号都是TTI电平，驱动能力和抗干扰性有限，实用中常配合其他总线实现互联，RS-485总线就是其中之一。RS-485总线是平衡差分传播，抗干扰性好，最远可传播4000m，可互联多达128个单片机，非常适台构成多机通信系统。在多机通信中，最重要是保证通信有条不紊地进行，因而需要严格通信合同和完善通信软件，本文将重点简介应用于某大型工程单片机多机通信协议和通信软件设计办法。本文简介一种运用单片机自身所提供串行通讯口，采用自定义串行通信合同，加上总线驱动器如MAX481、MAX483、MAX485、MAX487等组合成简朴RS－485通讯网络，完毕单片机间多机通讯。核心词：单片机；串行通信；RS－485总线：多机通信合同AbstractIncomputercommunicationfield.Becauseofthesinglechipmicrocomputerhasflexibleandefficientcomputercommunicationfunctionandpriceadvantage，usedmoreandmorewidely，butbecauseofthesinglechipmicrocomputertosendandreceivesignalsareTTIlevel，driveandanti-interferenceabilityislimited，practicalcooperationwithotherbusrealizeinInternet，RS-485busisoneofthem.RS-485busisabalanceddifferentialtransmission，anti-jammingofthegoodandasfaras4000mcouldbetransmitted，interconnectedasmanyas128singlechipmicrocomputer，verycomfortableacompositioncomputercommunicationsystem.Incomputercommunication，themostimportantistoensurethatcommunicationsinanorderlyway，andthereforeneedtostrictcommunicationprotocolandperfectcommunicationsoftware，thispaperwillfocusonintroducesappliedinalargeprojectsingle-chipcomputercommunicationassociationPutthecommunicationsoftwaredesignmethod.Thispaperintroducesamicrocontrolleritselfprovidetheserialcommunicationmouth，usecustomserialcommunicationprotocol，plusthebusdrivesasMAX481，MAX483，MAX485，MAX487combinedintosimpleRS-485communicationnetwork，finishbetweenthesinglechipcomputercommunication.Keywords：SCM；Serialcommunication；RS-485bus：computercommunicationagreement目录TOC\o"1-3"\h\z\uHYPERLINK\l"_Toc"第1章绪论PAGEREF_Toc\h1HYPERLINK\l"_Toc"1.1课题研究背景与意义PAGEREF_Toc\h1HYPERLINK\l"_Toc"1.2单片机多机通信发展PAGEREF_Toc\h1HYPERLINK\l"_Toc"第2章总体简介PAGEREF_Toc\h3HYPERLINK\l"_Toc"2.1系统构成PAGEREF_Toc\h3HYPERLINK\l"_Toc"2.2RS-485PAGEREF_Toc\h3HYPERLINK\l"_Toc"2.3多机通信原理PAGEREF_Toc\h4HYPERLINK\l"_Toc"第3章硬件设计及原理PAGEREF_Toc\h6HYPERLINK\l"_Toc"3.180C51单片机硬件构造PAGEREF_Toc\h6HYPERLINK\l"_Toc"3.2最小应用系统