工业无线网络标准初步了解
WIA-PA
其全称是《Wireless Networks for Industrial Automation Process Automation》,译为《面向工业过程自动化的工业无线网络标准技术》
国产标准,中科院沈阳自动化研究所提出的标准。
基于IEEE 802.15.4,事实上是在TI cc2430基础上进行了一些简单的网络约定。
WirelessHART
基于IEEE 802.15.4。
它的命名来自于HART (Highway Addressable Remote Transducer),HART是基于Bell202来实现的一个有线通信网络,使用音频FSK频移键控。其使用历史悠久,是全球智能仪表的工业标准。
就像它字面上的意思,他就是无线的HART,支持已有的HART设备是其最大的竞争优势。
ISA100.11a
也是基于基于IEEE 802.15.4。
是由The International Society of Automation制定的协议,也是这几个里面应用调研公司ONWorld的2007年度调研报告表明“55%的人计划采用ISA100技术,40%的人说计划支持无线HART”。但是ISA100.11a可以支持HART、Profibus、CIP、FOUNDATION Fieldbus等多个协议,具有更大的竞争力。
Zigbee
基于基于IEEE 802.15.4。
有线技术存在的问题:
- Pre-planning requirements, higher installation and maintenance costs of the wired network.
- Difficulty in troubleshooting connectors.
- Less flexible infrastructure due to fixed connections.
- Wired networks have to be designed with spare capacity on cards, marshalling cabinets, junction boxes and so forth, to cater for future expansion.
- Rotating equipment cause constant twisting of cables which results in fatigue and communication failure.
无线技术的主要优势:
- Wear-and free data transfer.
- Lower installation and maintenance costs.
- Deployment opportunities in mobile, and rotating equipment, and hostile and remote locations.
- Deployment opportunity for MEMS(Micro-Electromechanical Systems) technology, advantages of which include cost efficiency, low power, high performance sensing and integration.
- Fairly reliable communication without expensive connectors.