Answer / eswar

Plc is a simple computer which used for automation of real
world processes such as controlling of machinery in a industry.
Plc is a microprocessor based device with input and output
circuitry that monitors the status of the field connected
"sensor"inputs and controls attached output"actuators"
according to user created logic program.
application: maintaining the water level in a tank between
two float switches by controlling the electric valve.
Ladder diagram is a language which composes of program using
a relay logic symbols as a base in an image similar to a
hardwired relay logic sequence.
advantages
flexibility,pilot running,space efficiency,correcting
errors,visual observation

Answer / abdul ahad

I am Agreed with Answer # 1 and 2 .
PLC is Programable Logic Controller and we can used it for
any kind of the industries/home automation or semi-
automation ( As per our requirement ).

Answer / ankit arora

ladder programming is a language . ladder language is a
combination of input contacts and output coils for make a
logic programm.

Answer / priyaloges

The PLC is a controller device which is used to control the
logically automated systems.It replaces relays to a single
PLC.Fuctions are motion control, process control, networking
control,distributed controletc.,

Answer / nilesh yadav

A PLC has many "input" terminals, through which it
interprets "high" and "low" logical states from sensors and
switches. It also has many output terminals, through which
it outputs "high" and "low" signals to power lights,
solenoids, contactors, small motors, and other devices
lending themselves to on/off control. PLCs are industrial
computers, and as such their input and output signals are
typically 120 volts AC, just like the electromechanical
control relays they were designed to replace. Although some
PLCs have the ability to input and output low-level DC
voltage signals of the magnitude used in logic gate
circuits, this is the exception and not the rule.

Answer / himanshu patel

>A programmable Logic Controller (PLC) is a solid state/computerized industrial controller that performs discrete or sequential logic in a factory environment. It was originally developed to replace mechanical relays, timers and counters. PLCs are used successfully to execute complicated control operations in a plant................!!!

>It is field programmable by the user. It allows the user to modify the programs as per the requirements of a plant without having to send the unit back to the manufacturer for this purpose.
>Plant Automation is the necessity for the manufacturing industry to survive in today’s globally competitive market.

Answer / muthu kumar

PLC is a kind of processor which we can it use for any
applications, ladder diagram is a language which plc can
understand. there are so many advantages are there we can
use it for any applications but it is depends upon the user
needs and I/O of PLC.

Answer / dhara

A Programmable Logic Controller, or PLC for short, is simply a special computer device used for industrial control systems. They are used in many industries such as oil refineries, manufacturing lines, conveyor systems and so on. Where ever there is a need to control devices the PLC provides a flexible way to "softwire" the components together.

Answer / denish pastagia

Its Programmable Logic Controller, its a one kind of industrial Computer which is use to interface between Field input device and field Output Devices, Its Made for work in rough Environment, its microprocessor based Controller, With the using of Plc We can Develop Any Kind of Application like car manufacture unit, Bottle Filling Plant through Programming,
In Industry the mainly Use of PLC is like a main Controller Though Which We Controlled Every Instruments.
Its Reduces the Wiring Cost And The use of Plc We Easily Troubleshooting the Concept and Hardware. 

Answer / shanmugaraj s

plc is programble logic controller , plc main use of real
tmie relay and timier and counter is replacedto the fully
programing use. the main application of all industry
automation is using plc ladder diagram.convery control,
water filling control , counting application , fully
automation process.. plc advantage is flexiblity,compact
size, program is very easy, easily control the all component

1.what is the effect of vapour presuure in orifice plate flow measurement 2.which is more effective 2 pressure sensors or one single differential pressure sensor in orifice plate measurement 3.how to design a v/i converter and i/v converter 4.how many type of thermocouple are there 5.how many leads are there in thermocouple measurement 6.how pressure sensors are connected in level measurement in differential pressure method 7.what is the output of capacitive pressure sensor (ac or dc),how its o/p is signal charactarized 8.what is the physical meaning of discharge coeeficient,why it is calculated,orifice plate what is its value,why it is less than 1,Q at upstream is equal to or not equal to Q at downstream of orifice plate why?what is vena contracta in orifice plate 9.why rotameter is called variable area flowmeter,it can measure flow even if area is not varying,why it is made tapered 10.design a 10 bit counter ,which counter you will prefer 11.how to remove self heating error in RTD 12.which is more sensitive pt100 or pt50 13.why thermocouple are connected in parallel 14.what is lead contact error in RTD,how to avoid 15.what is P,PI,PID,PD controller,why there is no ID controller 16.what is override,split range,sequential,ratio,feedforward,cascade controller 17.why we moved from SR to JK and then JK to master slave JK flipflop,give correct reason 18.how to measure level of a closed container which contains vapour and liquid,remember no vapour gas should be leaked,so ultrasonic and capacitive is not an option,design another method 19.how to design horse race counter including sensors and signal conditioning element 20.what is bevelling

0 Answers   BARC,

what is cascade system ?

1 Answers   RSP, Thermax,

why most of the DP transmitters using maximum range as 0-2500mmwc?why not 1000 2000 3000 4000mmwc

2 Answers   SPIC, TNPL,

Explain Gas Turbine startup and shutdown sequences

0 Answers  

why we use condesiate parts before tranmitters?

3 Answers  

what is the principal of flow transmeter,level trans meter,presser transmeter?

11 Answers   Nestle, Reliance,

EXPLAIN NETWORK COMMUNICATION ON DCS?

0 Answers  

Dead weight tester & comparator for calibration , which is more accurate , what is the application.

1 Answers   Bapco Bahrain Petroleum Company,

Which types of quections asked in interview for FORMULATION PLANT (PHARMA)

0 Answers  

what is diff between the centrifugal and reciprocating

2 Answers  

In RTU Panel we are having several Analogue & Digital Inputs /Outputs. We are recently facing some problems over Analog inputs , which are not updating properly (But Digital Input are updating normally) Can any one tell me from where the problem is creating , we have checked PLC CPU card, Analog Input card & we reconfigured ,But still the issue is there. Issue : 1. Sometimes Analog values are updating & sometimes not. 2. Analog values are not updating normally , showing some wrong Values 3. Total dead (0 value) Analog values are Level & flow measurement from the field instruments. (But in field the instruments are working normally & Displaying the values normally in local display unit) This problem we are facing in our Water Plant. If any one experienced this same problem or having any ideas related to our issue PLS send your valuable Answers/Replies...

6 Answers   L&T,

in yokogawa prosef rd safety PLC how to data send frome local SCS to other SCS and other FCS

2 Answers