Tag: control systems
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Basic Features of Distributed Control Systems (DCS)
In distributed control system, each process has its own separate controller located at the site. These local controllers are interconnected via a local area network so that all controllers on the network can be monitored or reprogrammed from a single … Read more
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Proportional-Integral-Derivative (PID) Control Systems
Proportional-Integral-Derivative For processes that are able to operate with continuous cycling, the relatively inexpensive two position controller is sufficient. For processes that cannot tolerate continuous cycling, a proportional controller is used. For processes that tolerate neither cycling nor offset error, … Read more
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Proportional plus Derivative (PD) Control System
Proportional plus derivative (rate) control is a control mode in which a derivative section is added to the proportional controller. This derivative section responds to the rate of change of the error signal, not the amplitude as with the integral … Read more
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Why you should replace your old DCS systems with modern ones
To keep up with evolving technology manufacturers need to upgrade their legacy Distributed Control Systems (DCS). This might be a challenging task to undertake and at a cost to the company, but in the long run the benefits outweigh the … Read more
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Proportional Plus Integral (PI) Control System
This type of control is combination of two control modes, proportional and integral (reset). The Combining of the two modes results in gaining the advantages and compensating for the disadvantages of the two individual control modes. The main advantage … Read more
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Basic Features of Programmable Logic Controllers (PLCs)
Introduction to Programmable Logic Controllers What is a Programmable Logic Controller? A PLC is a user friendly; microprocessor-based specialized equipment that carries out many types of control functions with levels of complexity for use in industrial automation applications. Its objective … Read more
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Integral (Reset) Control Systems
Integral (Reset) control Reset/Integral control describes a controller in which the output rate of change is dependent on the magnitude of the input. Specifically, a smaller amplitude input causes a slower rate of change of the output. This controller is … Read more
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Proportional Control Systems
The control mode In the proportional control mode, the final control element is throttled to various positions that are dependent on the process systems conditions. The controller operates within a band that is between the 0 % output point and … Read more
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Process Time Lags and Stability of Automatic Control Systems
Processes have the characteristics of delaying and retarding changes in the values of the process variables. Process time lags generally describe these process delays and retardations. Process time lags are caused by three properties of the process. They include: Capacitance… Read more
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What is the Controller?
A controller is a device that generates an output signal based on the input signal it receives. The input signal is actually an error signal, which is the difference between the measured variable, and the desired value, or setpoint. The … Read more