ISA’s 2015 Process Control & Safety Symposium

Houston Marriott Westchase | 09-12 Nov 2015 Seven ISA Divisions Team up For Event The 2015 Process Control Symposium-Sponsored by Process Measurement and Control, Safety and Security, Chemical and Petroleum, Communications, Education, Pulp and Paper, Management Division of ISA and … Continue reading

September meeting showcases industrial wireless networks

Tour guide

Kevin Lavelle at right, Northeast Regional Sales Manager for our meeting host Endress+Hauser, served as tour guide to explain the whys and wherefores of the company’s new demonstration and training facility featuring flow and level instrumentation.

Downstairs

Downstairs view

Upstairs

Upstairs view

Speaker Joe Kurcon

Joe Kurcon, Senior Account Manger for Endress+Hauser, spoke on industrial wireless sensor networks.

Joe Kurcon of E+H provided the program content for the meeting. He started with a surprising item of trivia: the relationship between wireless networks and the late actress Hedy Lamarr. Mathematically talented, she and composer George Antheil are co-holders of the earliest patent for spread spectrum communications and frequency hopping–the basis of industrial wireless. (Music, when you think  of it, is a series of hopping audio frequencies). They presented the idea to the U.S. Navy during WW II to deal with torpedo guidance to overcome enemy counter-measures, but the Navy ignored the idea (not invented here).

Kurcon explained the difference between two types of spread spectrum technology: FHSS and DSSS radio systems. FHSS signals quickly hop through multiple frequency channels. The transmitters and receivers are synchronized. DHSS radio systems spread a narrow frequency source by integrating it with a pseudo-random noise signal that widens it throughout a band.The receiver knows how to eliminate the noise.

He said that FCC rules permit use in three bands: nominally 900, 2400, and 5800 MHz. The highest band reaches the smallest distance so is infrequently used. The rules permit up to one watt of power without end-user licences. Kurcon went on to discuss network wireless topologies, such as point to point, star, and mesh.

He continued with a discussion of WirelessHART, which evolved out of the HART protocol in which digital information is superimposed on a 4-20 ma analog signal. WirelessHART enables users to quickly and easily gain the benefits of wireless technology while maintaining compatibility with existing devices such as flow, temperature, and pressure transmitters.

Usually a WirelessHART adapter connects to the existing HART instruments, forming a mesh network. Data can flow from any adapter to any other, avoiding interference from obstacles that come and go. The signals connect to a gateway that routes them via a wired fieldbus to control computers.

Kurcon concluded with some practical applications from his experience at Endress+Hauser. He said the office has a full-time person who deals with industrial wireless systems, but he happened to be in Germany at the time of this meeting.

Link to more meeting photos.

September meeting topic: Industrial Wireless Sensor Networks

Market interest in wireless industrial devices is growing rapidly in the process industries as their capabilities improve. Standardization of wireless network protocols for both devices and infrastructure makes the technology even more attractive. Interfacing these devices using standards such as … Continue reading