Integrating wireless instrumentation
As one of the major suppliers in the growing field of industrial wireless, Honeywell Process Solutions (HPS) has prepared a brief but useful whitepaper on the topic: Wireless Process Control Network Architecture Overview—Industrial Wireless Networks Gain Acceptance on Plant Floors . Here’s an excerpt from the paper:
“So how can a company design a network infrastructure that will connect the wireless network to the wired network securely and reliably? How many wireless networks are required to support these applications?
“The first step is to select the wireless network or networks capable of supporting the various standards used by the many devices existing in or planned for your plant, i.e. 802.3 for Ethernet based devices such as IP cameras, 802.11 for Wi-Fi devices such as handhelds, cameras and finally ISA100, Zigbee, WirelessHART, or Bluetooth for wireless transmitters. For control level applications, the wireless gateways connecting the wired network to the wireless network need to support the most common industrial communication protocols such as Foundation Fieldbus, HART, Modbus, Profibus and OPC. Plants can either implement dedicated wireless networks for each standard or a single universal wireless network capable of supporting all these standards. Honeywell is one of the suppliers that offers a single and universal wireless networks capable of supporting 802.3, 802.11 and ISA100 devices.
“The second step is to design a network architecture that securely connects the wireless network or networks to the wired network. In order to design a robust and scalable architecture, the company needs to clearly identify all applications and their users that will leverage the wireless network. Some data needs to go to applications hosted on the business network and others are used by applications hosted on the control-level network. For example, a mobile station providing process data needs to be connected to the control-level network. A handheld used during operator rounds also needs access to the control-level network. But the same handheld might need access to the work-order application which resides on the business network. Wireless transmitters will require access to a device level network.”
While HPS is a contender in some of today’s wireless standard battles and builds integrated control systems, this paper is largely non-sectarian and should be beneficial to anyone considering expanding into wireless technology, regardless of platform preferences.
If you’re in initial stages of exploring wireless instrumentation, this can help you understand how to make a secure connection from devices that set up their own networks, to your control environment.
Also read The Transparency of Wireless in the April 2009 Control Engineering .
—Peter Welander, process industries editor, PWelander@cfemedia.com ,
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