Process Industry plants one of the biggest expenses during installation is the cost of wiring. Many field instruments are located 100s of metres away from the control room. And every connection metre requires the use of special copper cable.
Even with a fieldbus like PROFIBUS which is designed to use a single cable approach to connections, there can be many miles of copper cable on a plant. Hence the great interest in wireless connections.
There are other reasons for using wireless connections. For example, a tank or vessel may be located in a highly corrosive environment, or in an area which is hard to reach. Thus, wireless can be an efficient and convenient way to connect, as well as saving money in design, engineering and installation.
PI has collaborated with other fieldbus organizations in opting for the existing WirelessHART solution developed by the HART Communications Foundation as a means of connecting field instruments to a network. HART, one of the original digital communications systems, is based on the widely-used 4-20mA standard and has an installed base of around 24,000,000 devices. So, allowing easy connection of these into PROFIBUS is an obvious way to help industrial users get more from their plant instrumentation AND migrate easily into a fieldbus future.
WirelessHART is based on the IEEE802.15.4 standard and uses a 'mesh' approach to connections that ensures self-configuration of a WirelessHART network, flexible coverage and reliable redundancy options that provide full security.
A universal adapter links WirelessHART to any PROFIBUS or PROFINET network, ensuring data to and from wireless devices is conveyed to all parts of a plant quickly and easily.