Differences between DAS and SCADA in the iIOT
The Evolution of technology
The evolution of technology and greater access to the Internet has allowed more and more devices connected to the Internet every day. This is known as the Internet of Things (IoT). In addition, if this concept is applied to industrial systems, it is called Industry 4.0 or Industrial Internet of Things.
There are many applications and fields where the previous terms can be used, such as in the monitoring and control of wind farms or in the optimization, consumption and distribution of energy (SMART GRID).
These applications and fields are mainly based on two systems: DAS (Data Acquisition) and SCADA (Supervisory Control and Data Acquisition).
DAS / DAQ (Data Acquisition)
Acquisition systems (DAS or DAQ System) arise during the first industrial revolution, although they were used at the beginning of the 1920s in long distance communication systems, such as telegraphy.
Generally, the architecture of a data acquisition system consists of sensors, an acquisition device and a personal computer.
The sensors convert physical phenomena, such as the temperature of a room, the intensity of a light source or the force applied to an object, into electrical measurements.
The acquisition devices or DAQ devices act as an interface between the computer and the signals coming from the sensors. Basically, they digitize the electrical signals and condition them to be interpreted later by a software application on the PC.
The main function of the computer is to execute a software application that processes, displays, stores and sends the readings of the sensors to data servers through the Internet. Thus, they can be analyzed later and be available to the users at any time and from any place.
SCADA (Supervisory Control and Data Acquisition)
SCADA systems (Supervisory, Control and Data Acquisition) emerged in the 1970s in response to the need to inspect and operate several increasingly complex processes remotely. They allow engineers to look for solutions in a more efficient way.
In general, they are defined by implementing concepts of great utility and necessity, such as the monitoring, control and automation of processes, as well as to carry out supervisory tasks on the elements that make up the process.
Thanks to the industry 4.0, in other words, the automation of factories, operators can supervise if the production is being carried out correctly in safe plants, apart from providing greater flexibility to them and a savings in infrastructure costs.
DAQ/DAS |
SCADA |
|
Open and flexible architecture | NO | YES |
Compliant with safety and reliability standards | NO | YES |
Low latency and upgradability | NO | YES |
Entire process manually controlled | YES | NO |
Entire process automatically controlled | NO | YES |
Process monitoring and alarm definition | YES | YES |
Process evolution remotely controlled | NO | YES |
Interaction with devices such as valves, sensors, motors, pumps… | NO | YES |
Predictive maintenance option | NO | YES |
Massive data analysis | YES | YES |
Inclusion of the system into a PLC (Real Industry -> SCADA + PLC) | NO | YES |
Full connectivity between different industrial applications and databases | NO | YES |
Compliant with safety, reliability, low latency and upgradability standards | NO | YES |
In summary, SCADA systems offer many advantages over DAQ acquisition systems, not only in terms of control and supervision but also in flexibility and integration with different industrial systems. Besides, they are ideal for the development of control and monitoring applications of the Industrial Internet of Things type (IIoT).
The apparition of FACTS (Flexible transmission Systems), Direct Current trunk grids and microgrids will get better the electrical system through the Smart Grid.
In a vast majority of cases, SCADA systems need to be implemented for a correct monitoring of the evolution of the processes, as well as an exhaustive control of those processes. It is not only recommended but mandatory if you want to obtain satisfactory results, save analysis costs and time and provide flexible solutions to both engineers and operators according to their needs.