Field instrumentation is a key component of any SCADA system. In this post we will throw light on how field instruments have evolved and influenced the process control methods. In order to control any manufacturing process you need to have instrumentation to monitor the process parameters. Pressure gauges and temperature gauges are used for measuring pressure and temperature of the process. Similarly, tachometers are used for measuring speed and level gauges are used to determine liquid levels. These are all filed instrumentation that captures process data.
The days of physical control
In earlier times, operators used to monitor the data by observing it physically and used to take control actions manually. Like opening and closing of valves or starting and stopping of pumps. The first move towards automation was observed when limit switches were fitted to these instruments. This would enable the instruments to be stopped on its own whenever the set parameter was deviated. It improved controls as it was no more necessary to depend on human abilities to detect deviations that necessitated stoppage of the equipment. Gradually feedback sensors were introduced and actuators were added to the control system for more precise and accurate control.
Need for automation
It was during the later stages that the need for data acquisition was felt. This was necessary not only for process control but the historical data would provide more information about the process limitations and provide opportunities for improvement. Thus the wired instruments were connected to a local PLC unit to perform the control function better. However, the controls were still localized.
Then came a time when the need for remote process control became imminent. This paved the way for the introduction of the SCADA system that changed the landscape of process control. Since then, there has been no looking back as SCADA is what the industry swears by today.
The days of physical control
In earlier times, operators used to monitor the data by observing it physically and used to take control actions manually. Like opening and closing of valves or starting and stopping of pumps. The first move towards automation was observed when limit switches were fitted to these instruments. This would enable the instruments to be stopped on its own whenever the set parameter was deviated. It improved controls as it was no more necessary to depend on human abilities to detect deviations that necessitated stoppage of the equipment. Gradually feedback sensors were introduced and actuators were added to the control system for more precise and accurate control.
Need for automation
It was during the later stages that the need for data acquisition was felt. This was necessary not only for process control but the historical data would provide more information about the process limitations and provide opportunities for improvement. Thus the wired instruments were connected to a local PLC unit to perform the control function better. However, the controls were still localized.
Then came a time when the need for remote process control became imminent. This paved the way for the introduction of the SCADA system that changed the landscape of process control. Since then, there has been no looking back as SCADA is what the industry swears by today.