前言 PowerDNA(指分布式联网的自动化和控制—Distributed, Networked Automation and control)是一种旨在以太网上建立新的硬实时I/O基准的系统。近几年,以太网已支配工厂级网络层,就好像选择PC主板作为工业控制硬件平台的情形,其原因非常相似。首先,商业市场的需求量,从而使得价格降到最低。其次,由于这些技术已被人们普遍地采用,它们有广泛的设计工具支持,因此大部分工程师对这些技术不但很熟悉,而且体会到应用它们创建系统十分方便。同时,工程师们还发现以太网的芯片只需几个 Preface PowerDNA (Distributed, Networked Automation and control) is a system designed to establish a new hard real-time I / O benchmark over Ethernet. In recent years, Ethernet has dominated the factory-level network layer, as if the choice of PC motherboard as the industrial control hardware platform, the reason is very similar. First, the demand of the commercial market, so that the price is minimized. Second, since these technologies are commonly used and have broad design tool support, most engineers are not only familiar with these technologies, but also appreciate the ease of applying them to create a system. At the same time, engineers also found that only a few Ethernet chips