The use of industrial wireless networks based on standard ISA-100.11a and protocol WirelessHART in process control

This article considers wireless technologies in the field of automation of technological processes and production in the energy, chemical, petrochemical and oil refining, gas, railway, mining, metallurgical and other industries where the use of wireless industrial devices is necessary due to specific features. Wireless technologies provide the ability to connect measuring devices directly to the wireless network with further transfer of information through a wireless gateway to an automated control system. This article will discuss the types of wireless networks that are classified according to the possible range of action (Wireless Wide area network, Wireless Local Area Network, Wireless Personal Area Network). The most common standards of organization of wireless industrial networks, including IEEE 802.11 b/g/n, IEEE 802.15.1, IEEE 802.15.4, IEEE 802.16 e, will also be considered, including in the field of management of chemical-technological processes and productions. Data transmission protocols ISA-100.11.a and WirelessHART and a number of their features will be analyzed. The basic standard network structures based on the ISA-100.11.a and WirelessHART protocols, their typical components, will be considered. The article provides an analytical comparison of the ISA100.11a and WirelessHART over the OSI network model layers, including the physical layer, the link layer, the network layer, the transport layer, the session layer, the presentation layer and the application layer (process control, management, security, application sublayer). The main stages of calculation of wireless industrial network are given, in particular: calculation of the network information load, calculation of the network’s energy parameters, frequency-territorial planning, development of the communication scheme and interface with external networks. The formulas for calculating the network information load using Nazarov’s methodology, calculating the network’s energy parameters, taking into account the overall losses in the propagation of radio waves, including losses in free space, losses in partitions and walls inside the building, losses due to interference and signal fading are given.