RS-422和RS-485的区别

硬件: Modular Instruments>>Digital Transmission Analyzers>>PCI-6810, Modular Instruments>>Digital Transmission Analyzers>>PXI-6810

问题:
RS-422和RS-485两种协议的区别是什么？

解答:
RS-422（EIA RS-422-A 标准）是用在苹果的Macintosh电脑上的串行接口，而RS-485（EIA-485 标准）通常用在IBM-PC兼容机上。RS-485是RS-422的扩展集，也就是说所有RS-422设备都可以用RS-485来控制。这两种协议都支持多点通讯，但是RS-485在RS-422的基础上作了改进扩充，同一总线上的最大设备数量由422支持的10个变成32个。对于这两种串行通讯协议，您都需要自己添加终端匹配电路。关于终端匹配电路的更详细的信息，请参考知识库 0XE8M4L7。

相关链接:
White Paper: RS-232, RS-422, RS-485 Serial Communication General Concepts
KnowledgeBase 06R9GIRV: RS-485 and RS-422 Compatibility and Multidrop Information
KnowledgeBase 0XE8M4L7: What is Termination and Biasing? Do our Serial boards come with Termination and Biasing resistors built-in?

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报告日期: 06/27/2006
最近更新: 10/09/2015
文档编号: 1HDDKDB7