Answer / rajkumar r

PLC-PROGRAMMABLE LOGIC CONTROLLER,used for
automation...earlier we used hard wire logic control and
then logic gates..PLC s the advance system inwhich we can
program the fuction what s to be carried out. Main
advantages of PLC:

1.Less number of wiring
2.process can be modified anytime by programming online
without disturbing any ongoing process.
3.Fault identification s very very easy which in turn
machine breakdown time will come down. Ultimately increase
in production.
4.Easily can be linked with any operating panels like HMI
to communicate with other process related systems..

PLC has Input module,O/P module and a processor. The field
inputs like a switch,sensors will be connected to Input
modules whereas field outputs like motor
starter,relays,valves etc. will be connected to Output
module. The program for assigned function will be stored in
processor with help of programming software given by PLC
manufacturers. For basic knowledge about PLC pls visit
PLCS.NET website.

Answer / a.muthukumar

PLC is a Programmable Logic Controller.PLC is having CPU
and Input module and output module.CPU reads the status of
inputs ,Executes the program logic and Writes the status of
outputs.PLC having some programming languages like Ladder
logic,Function Block diagram,Structured text,Sequential
function chart.PLC is having soft wiring program,If is
required to change the logic is vary easy compare to Hard
wiring.

Answer / bhuvana

PLC is used instead of Relay circuits
It is reduced wire circuit

Answer / bharath

programmable logic circuit

If a warning lamp will operate with the ground circuit is bypassed with a jumper wire to ground, what should you check?

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what is the protection system in solar turbine compressor

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I want to measure level under vaccum by using DP Tx and vaccum vary between -500 to -670 mmHg and process fluid is accetic anhydride if consider process fluid density 1 kg/cm2. how to calibrate Tx ? consider level is 0 to 100 Cm.

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Hi buddies! my name is sachin and i am working as a electrical and instrumentation engineer in a paper plant. right now i am facing a problem and if someone could help me it will be an immense pleasure to me. i am using AC 800M to synchronise DCS500 drives on paper machine and rewinder.communication is on PROFIBUS and we are using NPBA-01 module to link profibus to DC drives.But these days two of these drives are showing a error named FIELDBUS COMM.TIMED OUT and the drives get tripped.I have changed the NPBA module and PROFIBUS cable.So if anyone can do please help me out with this problem.I'll be highly grateful.

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for indiacation of turbine(china) bearing temperature what type of sensor will be used(i.e. rtd or thermocouple or themister ) ? why it is ? i need clear explanation ?

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what is zero and span ?

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1. How many output signals do wew have in process control? 2. Could you write down the names of the pre-commissioning and commissioning stage test instruments and explain them (more than 5 items)? 3. What is the first step to commission a transmitter on service? 4. What is RTD? 5. Find the output value in MA of a temperature transmitter (RTD Type) at 120degree celius? 6. What is the O/P signal of a pneumatic transmitter? 7. What is the O/P signal of an elctronic transmitter? 8. What is the close loop and open loon?

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generally transmitter power supply having some range(12v to 35v) but the out put(4-20 mA) must same for given input.If we vary the power supply voltage then output mA also to be change according to V=IR. Is there any voltage regulator in the transmitter ?

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Explain bernoulli’s theorem. State its application.

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how u calibate pr tx without master tx?

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how can check the loopchecking for valves?

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what is difference between differial pressure & delta pressure?

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