This issue of Automation World’s Industrial Ethernet Review takes a serious look at how Ethernet has begun to invade the fieldbus turf. Ethernet, and its companion standards, transmission control protocol (TCP) and Internet protocol (IP), are the corporate information technology standard, and are widely used for controller-to-controller and controller-to-server communications. It’s increasingly used for communication to the input/output (I/O) layer of automation.
想要将以太网用于I/O的工程师的主要关注点是确定性。以太网基于概率理论。数据被捆绑在一起，分支机构，数据包被散布在网络上，只有当它们全部到达目的地时才会重新组装。如果网络在尝试发送一个数据包时忙碌，则系统只需重新验证直到开口。因此，逻辑问题是出现的，数据包将到达I/O点的时间，以使设备执行预期的时间。但是，正如专栏作家吉姆·平托（Jim Pinto）在5月刊《自动化世界》（第70页）中指出的那样，当网络速度以100兆位/秒为单位，接近1千兆位/秒时，确定论问题通常会消失。
Follow-up Webcast
本月出版物中的信息将于6月8日扩展到网络广播中，其中包括著名的工业网络专家迪克·卡罗（Dick Caro）和具有现实世界经验的系统集成商和工程师Lou Bertha。这也是您向他们提出棘手问题的绝佳机会。如果您不这样做，我会的，因为我将成为这一主持人。您可以在www.myenum.com/webcasts.
内容
页：2 Ethernet Enters New Field: An aging fieldbus system was causing too much aggravation for engineers and technicians at Radiator Specialty Co.’s Charlotte, N.C., factory. Networking glitches became so common that technicians created a workaround so that many of the workers on the plant floor could restart the network. Engineers turned to Ethernet for a solution
页：9 Web Protocols: Internet protocols are becoming the norm in factory automation networks.
页：15 Ethernet Products
