Answer / laxit

Question is wrong, Now a days, PLC with mega expansion
capacity is available. One need to check the scaning time
requirement and avaiblity isues pertaining to process




For a large system DCS system for control is acceptbale
however for safety function there shall be PLC (ESD)
system. In case of small application where as PLC can work
as safety and control purpose shall employed.

Answer / lalit

plc cannot handle or show analog value...DCS HAVING
SPECIALITY TO MEASURE AND CONTROL ANALOG I/O RELIABLY

Answer / rambir singh

DCS and PLC are same in functioning but the difference is that DCS can display what happening inside PLC.

hii my name is sujith...i am preparing for HPVL GET 2010... so ,,,pls help me by send any previous questions or material to my site.....(Msujith_12@in.com) thank q

0 Answers  

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kindly sent some demo question and answer

0 Answers   HPCL,

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In power plant to measure vibration of a turbine we install sensors. Before install this sensor we have to set gap voltage. What is meant by gap voltage and its use?

0 Answers  

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i want to measure temp of hot sand(welding flux) in closed chamber(around 150 deg C).Which is better thermocouple or thermometer?

1 Answers  

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What is close loop ?

1 Answers   College School Exams Tests, GMR,

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A PLC is programmed to drive three motors A, B and C as follows : After running motor A for an hour, motor B should get ON and motor A should get OFF. And after running motor B for an hour, motor C should get ON and motor B should get OFF. And after running motor C for an hour, motor A should get ON and motor C should get OFF. (That is, a cyclic repetition with time period one hour) Now, the second condition is: If any motor gone faulty and is tripped, the consecutive motor should get ON and the faulty (tripped) motor should be eliminated from cyclic repetition. The remaining two motors should bear the cyclic repetition of one hour each. (For healthy motor take logic as high and for tripped motor take logic as low) Now, the third condition is: When motor A load(Amps) exceeds 60% of its rated load, motor B should get ON in parallel to motor A. And when both motors A & B are running in parallel, and if their load exceeds 60% of their rated load, motor C should also start in parallel to A & B. [Here the cyclic repetition is eliminated, until their loads become normal(40%)] [Take logic high(1) for load at 60% and logic low(0) for load at 40%] Now draw a flow chart or a ladder diagram to fulfill the above condition.

0 Answers   MNC,

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What is mean by Ethernet, Device net and Control net? For what application we are using these?

4 Answers  

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how to calibrate temprature switch and flow switch ?

1 Answers   Adgas,

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What is SCR?

9 Answers  

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what is the main supply source for pressure transmitter?

1 Answers  

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what is ment by PID controllers? explain with example?

2 Answers  

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how its work inductive proximity sensor explain briefly?

1 Answers  

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