"Hands and Eyes" of an Automated System

Field Level in Automation System.

In a previous article, we briefly discussed the automation system and we explored its definition and its role not only in the control of industrial processes but also in all our daily lives. We stated that it uses modern technology like PLCs, computers, robots, and artificial intelligence (AI) to optimize the operation processes by minimizing the human interface and achieving maximum efficiency with minimum cost and the highest quality.

We explained generally the 5 standard control levels of the Automation pyramid (shown in the below figure) which are: field, control, monitor, and management levels. In this article, we will explain in detail each level and its role in the automation pyramid. Let us start with the first one which is Field Level.

      Automation Pyramid

Field Level.

The field level is lying at the bottom of the Automation Pyramid. It is the basic layer that bridges the production process and the higher Automation control levels. It contains the field instrumentation devices that collect data from the site and the devices take actions and connect it to the PLC I/O hardware to be followed in the next level of control.

These devices included in that level are directly connected to the physical process. It could be sensors or transmitters that measure physical parameters like temperature, pressure, flow, light, position, level, vibration, and proximity sensors. These sensors convert these physical signals to electrical signals and deliver them to the input modules of the PLC.

After the control action taken by the PLC, the control signals from the PLC’s output modules are delivered to the field actuators and motors to perform physical actions, like opening valves (like Shutt-off and control valves in the gas train valve), driving motors, or moving robots or robotic arms. The field instrumentation also includes the interface modules of High Voltage (HV), Medium voltage (MV), and Low voltage (LV) switchgear. The field devices also contain all the local control panels and PID controllers.

            Field Level

What are the main Functions of the Field Level?

1. The field level is used for Processing, monitoring, and giving Feedback through the instrumentation devices. It continuously monitors the processes and provides feedback to help enable dynamic adjustments to keep the required high quality and performance.
2. The field level acquisitions the real-time data collected by sensors like temperature and pressure sensors from industrial processes to optimize the operation and ensure the human and machine’s safety.
3. The field level communicates the upper control level with the field instrumentation through certain wired and wireless protocols such as Profibus, Modbus, and HART.
4. The field level converts the electrical signals that represent the PLC’s output command to physical action like opening or closing gates, valves, and actuators as well as starting motors.

What are the technologies used at the Field Level?

• Technologies for Sensing and Monitoring.

• Industrial Internet sensors (IIoT).

• Smart and remote Sensors and Actuators.

• Wireless Communication.

• Profibus communication.

• Bluetooth and Radio frequency identification (RFID).

• RTUs (Remote Terminal Units).

• HMI (Human-Machine Interfaces).

• Field Robots.

• Renewable Energy Sources.

• Thermal Imaging.

• GPS and Navigation.

• Mobile Apps.

• LiDAR and Photogrammetry.

What are the advantages of the field level?

1. Improving the efficiency and productivity of the process by increasing the operation speed, reducing the cycle time, reducing the machines’ downtime, and utilizing the materials, labor, and energy resources.
2. Real-time monitoring and control by detecting and responding to the deficiencies, operating and troubleshooting the process remotely, and finally collecting data continuously to make good decisions from the tracking and data analysis.
3. Enhanced the accuracy of the process by avoiding human errors, making the product quality uniform, and making instant adjustments during operation to keep the high quality of the product.
4. Cost saving by lowering labor costs, reducing energy resources, and optimizing ongoing maintenance activities by enabling predictive maintenance and predictive plans.
5. Smart and Faster Decision-Making where Real-Time Data Processing enables automation, control systems, and AI to change the system’s conditions, providing a clear vision of the field operation and Improved System Visibility through advanced analysis.
6. Emission reduction and sustain the environmental resources where the online monitoring and tracking system at the field level enables the lowering of the carbon footprint allocates the sources that lead to the environmental impact, and integrates renewable energy resources to initiate the waste reduction in any industrial processes.
7. Increased Safety by reducing human exposure to hazards and dangerous operations. It also ensures a fast response in accidents and critical situations. It could be integrated easily into the fire alarm and firefighting systems.

What are the applications including the field level?

• Manufacturing and Production. Where is used in sensors and actuators, and quality control.

• Agriculture. It is used to enhance crop yields, Harvesting Automation, greenhouse gasses monitoring, and soil monitoring.

• Utilities. It is used in smart grid automation for energy management and energy distribution, water treatment in electricity generation stations, and renewable energy source monitoring and management.

• Oil & Gas. Used in refineries, pipeline monitoring systems, automatic drilling, and safety-enhancing.

• Transportation and Logistics. It is used in Traffic Control, Automated Warehousing, and Vehicle Systems to manage traffic signals, sort and store goods, and optimize operations and safety systems.

• Mining and Construction. It is used in Equipment Monitoring, Blasting Control, and material handling to ensure the safe operation of machines like crushers, conveyors, and loaders. To ensure also the safety during explosions.

• Food and Beverage. It is used in Batch Processing to regulate the mixing, cooking, and packaging operations.

• Used in Temperature and Humidity monitors to control the proper storage conditions. It is used also for Filling and Labeling to control the filling and ensure efficient labeling processes.

• Pharmaceuticals and Chemicals. It is used in Precise Dosing to control the chemical doses, and in packing and inspection to ensure the maximum safety and best quality.

• Environmental Monitoring. Used in Air Quality Monitoring: Sensors for pollution detection, and emission control, in Water Quality Control to monitor and control the pH, turbidity, and contaminants in water systems, and used in Waste Management to control, optimize, sorting, recycle, and disposal processes.

• Healthcare and Medical Devices. It is used in Life-Support Systems to manage critical parameters in ventilators and dialysis machines, used in Diagnostics to ensure lab accurate and timely analysis, and used in Sterilization Control to monitor and control the temperature and pressure in sterilization equipment.