The theory may be very interesting, but what does it mean in practice? SCADA is a system, used for data acquisition or process control. Thus the processes communicate with various devices in real time. In this context, devices commonly called PLC (Programmable Logic Controller) can be applied. It is within the scope of the ICS (industrial control system) and the DCS (distributed control system).
In summary, the SCADA system gathers all the information brought from the devices that may be distributed by the factory, home or the industry. This way the stored data is employed for statistical reporting or quality control. Speaking of frame layout, the system may be distributed across the network in the ICS or DCS. Another possibility is customization via HMI (human machine interface) and its use is programmed according to your application.
Following this theme, speaking a little hardware, each device has a communication protocol system that will define the driver that will be used in the SCADA system. Specific applications can also be customized via scripting. But not all scada systems have flexibility for any communication device. An example of SCADA system that has driver flexibility is the LAquis SCADA.
Types of communication system:
- RS-232 serial
It is one of the most economical options, but they are used for short distances. Uses 4 to 6 wire cable with DB9 connector. It has capacity for only one equipment.
- serial RS-485
Another more economical option. The cable has only 2 wires, commonly applied in industries. The distance can be up to 1Km and can be connected to several equipments in the same connection system. Optionally can be shielded from electrical noise.
This is the most expensive option, on the other hand is the faster than those mentioned above. Uses RJ45 network cable. It has capacity for various equipment, routers and Wifi.