Tag: process control
-
Pressure Control Valve Operation
A pressure control valve is a spring-loaded valve that is capable of maintaining a constant pressure in a system regardless of the flow rate. This is important, since most pumps e.g. gear pumps are constant-displacement types – a constant volume … Read more
-
Key Factors to Consider in Selection of Valves
Valves are the final element in a control loop, and are critical in providing the correct flow. The valve, usually operates in very harsh conditions, and is one of the most costly elements in the process control system. Their … Read more
-
Basic Steps to Consider in Designing a Control System
Typically a control system should be designed to work together with an already existing process. The control design problem can be stated at local, supervisory or even plant-wide level. If we consider the local level, the typical steps in designing … Read more
-
Fuzzy Controller and its Industrial Applications
Fuzzy logic is a human model, potentially applicable to a wide range of processes and tasks that require human instinct and experience. In computer, truth-values are either 1 or 0, which corresponds to true/false duality. In fuzzy logic, truth is … Read more
-
Basic Elements of a Digital Controller for a Steam-Turbine Driven Generator
The block diagram below illustrates the basic elements of a minicomputer system for speed and voltage control as well as data acquisition of a steam-turbine driven generator unit. Figure (a) computer control of a turbo generator unit Typical output variables … Read more
-
How Controllers are used in Industrial Automation Systems
In many process control systems, microprocessor based programmable logic controllers are used for decision making due to the sophistication of the system and the large number of process variables involved. The PLC can be configured to receive a small number … Read more
-
Basic Features of Controller Area Network (CAN)
Controller Area Network (CAN) is a serial communication protocol developed primarily for applications in the automotive industry. It is also capable of offering good performance in other time-critical industrial applications. The CAN protocol is optimized for short messages and uses … Read more
-
Technical Aspects of Foundation Fieldbus
Foundation fieldbus (FF) is an all-digital, serial, two-way communication system for industrial applications. Foundation fieldbus specifications include two different configurations: H1 and HSE. H1 Foundation Fieldbus (FF) H1 FF communication system is mainly applied to distributed continuous process control; … Read more
-
What is Fieldbus in Industrial Communication Networks?
Fieldbus can be defined as a digital, serial, multidrop, data bus for communication with industrial control and instrumentation devices such as sensors, transducers/transmitters, actuators, local controllers, etc. Alternatively, Fieldbus can be defined as a digital, two-way, multidrop communication link … Read more
-
RTD 2, 3, 4 Wire Sensor Connections
The resistance temperature devices (RTD) can be connected directly to the controller peripheral amplifiers using 2-wire, 3-wire or 4-wire lead configuration. The wires in all these connections are in shielded cables. The RTD is usually driven from a constant current … Read more