Answer / eswar

PLC is a small computer used for automation of real world
process such as control of machinery on factory assembly
lines.where older automated systems would use hundreds or
thousands of relays,a single PLC can be programmed as a
replacement.
example maintaining of water level in a tank between two
float switches by opening or closing an electric valve.
In this example plc accepting two digital inputs from two
float switches.The plc controlling a single digital output
to actuate the inlet value valve into tank.
advantages:
1 flexibility:one single Plc can easily run many machines
2with plc we can do any changes in circuit design and we can
correct the errors.
3 pilot running
4 visible observation
5 space efficency: todays plc's have more memory therefore
we can generate more and more contacts timers,coils,counters.

Answer / siddhesh

plc is a combination of solid state devices 2 perform
specific task using ladder logic
plcs are used to control certain process like power plant
or cement plant
its more reliable than pc,cost efficent initial
installation cost is more,more precise results are
obtained,small size

Answer / prabodh kumar

Definition = It is such a real time memory based controller which cab be programmed logically a/c to our requirement.

Use= in controlling any type of operation of machines.
ex- packaging machine of food, braveries, water

Application= in controlling action of any kind of not only machines but also lighting system

Advantages= By using this we can do a lot of work in short of time ,
it is real time operated device,
we can increase i/p & o/p
we can erase the program.

Answer / radha

Plc is like a processor in a mobile phone ..it is used to control devices by programming

How earthing can be checked????

0 Answers  

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A DP transmitter is used to measure the level of an open tank. The drain line of the tank is connected to a control valve, and is configured as, if the level of the tank is 90% the valve should get open 10%. And if the tank level is 10%, the valve should get open 90%. Draw wiring diagram and explain how to configure DP transmitter and control valve using HART communicator. If the span error at output is 1%, what will be the %opening of the control valve at 60% level of the tank?

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what is maximum temprature in instrumentation

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1)how we calculate the drum level? and how we select the transmitter range?

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what is the difference between servo valve & proportional valve

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