获取HART数据的新方法

除了4毫安(mA)模拟来讲ol channel in every Hart device, a second, all-digital channel provides access to real-time device status, diagnostics and multivariable information that resides within the device. When continuously monitored, this digital Hart data can provide valuable process information, such as advance warning that a device is about to fail.

但是在当今的工厂中，大多数这些有价值的数据仍然被困。根据Hart Communication Foundation（HCF）的数据，该领域约2500万个HART设备中约有85％与遗产，仅模拟输入/输出（I/O）系统连接，这些系统无法理解HART数字数据。

无线救援

The coming generation of WirelessHart adapters, based on the new WirelessHart standard, will enable users to rescue this stranded data and put it to use. When attached to installed Hart devices, or anywhere on the control loop, WirelessHart adapters will extract the digital data and transmit it wirelessly for use in asset management systems and other applications.

“我们有很多人要求他们。”关于他公司即将发布的无线智能无线THUM适配器的全球无线销售和营销总监Steve Ekblad说。埃克布拉德（Ekblad）不认为适配器市场将与符合新的无线仪器的仪器那样大。“但是我认为这将释放许多人们一直想做但无法做的事情，”位于明尼苏达州昌纳森的埃克布拉德说。

艾默生（Emerson）是六个以上供应商之一，他们计划在包括适配器在内的无线式产品的近期介绍。Ekblad说，艾默生将首先专注于新的无线产品。他说，将在本月开始在本月的一系列无线输入中开始，包括压力，温度和振动发射器。THUM适配器将稍后稍后出现：“大概在2009年初。”

Likewise at Pepperl+Fuchs Inc., Twinsburg, Ohio, Product Manager Robert Schosker says that P+F’s first WirelessHart adapters will be available during next year’s first quarter. Pepperl+Fuchs plans to offer battery-powered, loop-powered and line-powered adapter versions, with an emphasis on the battery-powered units, says Schosker. “By keeping it battery-powered, it eliminates any fear from the customer’s standpoint that the unit has any chance of interfering with the 4-20 mA signal,” he notes.

艾默生is taking a different approach. The Emerson Smart Wireless Thum Adapter will come only in a loop-powered version, and Emerson has no plans currently for a battery-powered version, Ekblad says. A loop-powered version can be attached without affecting the intrinsically safe approval rating of a device, he points out. “If you use a battery, you can’t hook it up to a device in an explosion-proof area, so that’s a really big deal.”

What’s the price?

Some industry watchers believe that a strong WirelessHart adapter market will depend on pricing being set at $500 or less. “Even $500 might be a little pricey,” opines Wil Chin, a research director at ARC Advisory Group Inc., in Dedham, Mass. Some Hart devices such as temperature transmitters are priced as low as $500 for the whole device, Chin says, so a $500 adapter might give some users pause. On the other hand, he notes, a $500 adapter price wouldn’t seem so bad as an add-on for a $5,000 to $10,000 Coriolis flowmeter.

在Pepperl+Fuchs，Schosker说，他尚未收到公司欧洲父母的最终无线适配器定价。他说：“但是我猜这将在每个循环250美元之间。”在艾默生（Emerson），埃克布拉德（Ekblad）表示，智能无线THUM适配器的初始价格将在每单位500至1,000美元之间。

Related Feature - Stranded Data: Wireless is the Key
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