Timer Off Delay.
Previously we talked about the timer on delay; now talk about timer off delay (TOF). At the end of the post it will show an example of a level control of a tank using timers. The timer is an output…
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Author Archive: miguel
Two and three-wire connection
Sensors with digital output to function properly need to consume power for operation of the control circuit. Furthermore, the output circuit must complete a loop with the power supply and the load. This is done connecting to two wires o…
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Can I connect a NPN sensor to NPN input?
My first job as an engineer was installing and configuring a PLC that my boss, who did not know much about the subject, he bought from a representative of a prestigious brand, but the seller did not know much about…
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DCS or PLC or PAC or RTU?
One often hears the question what is the difference between a PLC and DCS?, or question what is the difference between a PLC and RTU? This article the differences between these devices are clarified. Programmable Logic Controllers (PLC) The PLC…
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Sensors. Output Types.
In previous post it mentioned that the sensors have digital and analog outputs, however sensors also may have serial outputs, which can send digital, analog signal or both. Digital output An important aspect to consider is the type of output…
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Sensors. Definition and features
Sensors are a very important part of the instrumentation and control of industrial processes, are used to determine the status of the process where they are installed and transform the variations of the measured variable into an electrical signal conditioned…
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Operator interface
What is an operator interface? An operator interface is a device (or more) by which the operator gives orders to the controller of a process and receives from the controller the process current state. Operator interface levels There are a…
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Cross reference. Electrical Drawings
The cross reference is used to quickly locate items within the set of drawings, especially those elements whose parts are in different drawings. Grid location. Cross reference To find the elements in the drawing a coordinate system based on letters and…
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Types of drawings (electrical)
The electrical drawings describe different aspects of systems and generally, the electrical drawings grouped to the related or similar elements of the different aspects. This will include the following types of drawings in the same set of planes. Types of…
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Tag. Electrical drawings
In an electrical diagram for each symbol is associated with a Tag (name) which will identify the device within the set of drawings, other documents associated with the system and the device itself once it is installed in the field….
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