Tag: Industrial control
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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 of inputs (both analog and digital) and control a small number of outputs or the…
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Types and Operations of Wired Ethernet Networks
Ethernet plays an important role as a communication platform for automation systems. The Key strength of Ethernet is in its ability to run many protocols simultaneously on the same network. Ethernet enables flexibility, scalability and performance of industrial networks in a way not seen before in automated systems. Principle of Operation of Ethernet Network Ethernet…
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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 a carrier sense multiple access (CSMA)/Arbitration message priority (AMP) medium access control technique. Therefore CAN…
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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; running at 31.25 kbps. It connects digital field equipment such as sensors, actuators and inputs/outputs allowing…
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Topological Network Structures used in Fieldbus Systems
Topology is an important property of fieldbus. It is employed in the selection and definition of the best and suitable physical layout of the fieldbus network. The physical layer of the fieldbus has to meet somewhat demanding requirements like immunity to electromagnetic disturbances, robustness, intrinsic safety for hazardous areas, etc. The most important topologies for…
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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 among intelligent or smart measurement and control devices. It serves as a local area network (LAN)…
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Features of HART Communication Protocol
HART is an acronym for (High Addressable Remote Transducer). HART is implemented in two ways in industrial instrumentation networks: Point to point system Multidrop system HART Point to Point System Here serial communication data is superimposed onto a standard 4-20 mA loop signal as shown in figure 1(a): Frequency shift keying (FSK) is used with…
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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 source (I) and the voltage drop (V) across the RTD is measured. RTD 2-wire connection…
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How to Connect a DP (Differential Pressure) Flow Sensor to a DP Transmitter
The DP Transmitter should be mounted with a manifold block as illustrated in the figure 1(a) below to allow for maintenance. Valves B and C are the isolation valves while valve A is an equalizing valve. Valve A is used along with valves B and C to zero the transmitter. In normal operation valve A…
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Instrumentation Sensors and Transducers – Multiple Choice Questions & Answers (MCQ4)
The Answers have been provided at the end of the Questions: Q1. Which of the following sensors is used to measure displacement? A. Thermistor B. LVDT C. Dall tube D. None of the above Q2. Which of the below listed sensors is used for temperature measurement? A. Strain gauge B. Thermistor C. Piezoelectric crystal D.…