Intelligent devices, whether they are valve positioners, temperature devices, flow meters, or level meters, supply additional data such as secondary process variables or device diagnostics that can be used to obtain a better insight into the process.
This data can be made accessible using a HART data transfer protocol.
Although new control systems are HART enabled, the many legacy control systems in the field frequently lack the ability to collect HART data.
The WirelessHART standard can be used in both retrofit and greenfield installations, providing distinct advantages for each.
The time to engineer and develop the expansion or construction of a process unit can be drastically reduced by installing wireless systems to replace both infrastructure and signal cabling.
Moreover, investment costs as well as the costs associated with obtaining the necessary approvals are reduced.
A signal that previously took days to bring online using traditional wiring can now be commissioned within just a few hours using WirelessHART.
Less time and higher flexibility allows maintenance crews to deploy wireless nodes for temporary troubleshooting or adding "stranded" measurement points to increase safety or improve efficiency.
By utilising previously unused HART diagnostic data, a maintenance department can detect issues, for example plugged lines or worn valve seals.
Leaks and contamination may also be detected before they ever cause a problem to other instruments or the complete process.
What's more, plant personnel are protected against safety risks. A logistics department can better plan when to turn assets on and off.
What also should not be forgotten is that the efficiency of critical parts of plants and systems can be monitored from remote locations using WirelessHART.
The "Purdue Model of Process Control" explains how components in modern industrial networks collaborate.
It distinguishes between five levels in the hierarchical structure of a network of control systems.
With this model, users obtain a common model as well as standard terminology so that networks in all industrial application areas can be identically structured.
Each level has specified functions and actions for which it is responsible.
These responsibilities range from creating preventive maintenance schedules and equipment renovation cycles in level 4, to different types of local instrument control found in levels 0, 1, and 2. Levels 0, 1, and 2 are directly connected to level 3.
This involves manufacturing operations and control, which is directly responsible for establishing immediate production schedules and maintenance routines.
Having a better insight into the diagnostics data of the instruments installed in the plant or system makes it possible at level 3 to schedule maintenance routines more efficiently than in the past.
Level 3 can be considered a plant network, as it acts as a master of operations to the lower instrument control levels.
By integrating the WirelessHART gateway directly into the control network, additional controls are not required at the lower levels and new measurement points can be set up faster.
Directly connecting the WirelessHART gateway with the plant network has proven to be advantageous. This is because the DCS as well as other higher functioning plant tools, such as the asset management system (AMS), and HMI screens.