AUTOMATION USING PLC AND SCADA  

PLC

  PLCs have been gaining popularity on the factory floor and will probably remain predominant for some time to come. The advantages are:

       

plc block diagram
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• Flexible

• Cost effective

• Allow more sophisticated control

• Trouble shooting aids make programming 

• easier and reduce downtime

• Reliable components

As a control device, the PLC performs several functions. The PLC monitors input signals generated by sensory input field devices. Based on the input signals, the PLC makes logic decisions. As a result, the PLC takes control action by sending signals to the actuators of the output field devices. The input field devices provide status information to the PLC. The information is either the open or closed state of the field device or its voltage or current magnitude. The PLC reads the status information and stores a corresponding logic status value in the memory section of the CPU. Based on this value stored in the memory, the PLC solves the user control program which is designed to regulate the process.

After solving the user control program, the PLC takes control action by turning the actuators of the output field devices to either ON or OFF state. The PLC regulates the output field devices that control a process based on status information provided by the input field devices.

SCADA 

SCADA means supervisory control and data acquisition . It allows HMI (human machine interface). you can control process from your computer. SCADA  facilities animation. SCADA systems typically implement a distributed database. commonly referred to as a tag database, which contains data elements called tags orpoints. A point represents a single input or output value monitored or controlled by the system

SCADA systems are significantly important systems used in national infrastructures such as electric grids, water supplies and pipelines. However, SCADA systems may have security vulnerabilities, so the systems should be evaluated to identify risks and solutions implemented to mitigate those risks