Author: John Mulindi
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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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Features & Configuration of a Smart Pressure Transmitter
Smart/Intelligent pressure transmitters are microprocessor-based, and they provide additional functional capabilities beyond their basic role of just sensing and representing a process variable; for example they provide computing, diagnostics, and networking capabilities . We shall consider a capacitive sensing pressure transmitter with a typical functional diagram illustrated below: The process pressure is transmitted through the…
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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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Key Factors to Consider In Substation Design
Substations are the points in the power network where transmission lines and distribution feeders are connected together through circuit breakers or switches via busbars and transformers. This permits the control of power flows in the network and the normal switching operations for maintenance purposes. We discuss the key factors to consider when designing substations as…
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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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Features of FM Receivers
FM receivers employ heterodyne principle. The FM broadcast signals lie in the frequency range between 88 MHz and 108 MHz. The intermediate frequency (IF) of a FM receiver is 10.7 MHz which is much higher than the IF value of 455 kHz in AM receivers. Let’s consider the block diagram of an FM receiver below:…
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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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Types of Insulators used in Power Systems
We have various types of overhead line and substation insulators. Generally they can be classified as: Post Insulators The post insulators comprise of pedestal posts and solid core cylindrical types. Pedestal post insulators The pedestal post insulator stacks employed in substations are available as single units with a range of lighting impulses withstand ratings (LIW)…