General 1.What is Automation? Automationisdelegationof humancontrol functionstotechnical equipment forincreasingproductivity, better quality, reducecost &increasedinsafetyworkingconditions.2. What are the different components used in automation? The components of automation system include Sensors for sensing the input parameters Transmitters for transmitting the raw signal in electrical form Control system which includes !C, "CS & #" controllers $utput devices% actuators like drives, control valves. 3. What are the different control systems used in Automation? #" Controller based control system !C based control system "CS based Control system C &ased automation system 4. Explain PI !ased control system.#"'roportional #ntegral "erivative( isthealgorithmwidelyusedinclosedloopcontrol. The #" controller takes care of closed loop control in plant. A number of #"controller with single or multiple loop can be taken on network. #" Controllers arewidely for independent loops. Although some logic can be implemented but not muchof sequential logic can be implemented in #"s. ". ifference !et#een P$% & 'elay? !C can be programmed whereas a relay cannot. !C works for analog #%$s such a #" loops etc. whereas a relay cannot. !C is much more advanced as compared to relay. (. ifference !et#een P$% & %)? %)*The systemuses multiple processors, has a central database and thefunctionalityisdistributed. That isthecontrollersubsystemperformsthecontrolfunctions, thehistorynodeconnectsthedata, the#)Snodegivesreports, theoperator stationgives agood*)!, theengineeringstationallows engineeringchanges to be made. P$%*The systemhas processor %$+s and some functional units like basicmodules and so on. ,ses a SCA"A for visuali-ation. .enerally the SCA"A does notuse a central database. +. What is Encoder?A feedback device which converts mechanical motion into electronic signals. ,suallyanencoder is arotary device that outputs digital pulses which correspond toincremental angularmotion.Theencoderconsistsofaglassormetal wheel withalternating clear and opaque stripes that are detected by optical sensors to producethe digital outputs.Instrumentation )ystem,. What types of sensors are used for measurin- different parameters? Temperature sensors / 0T", Thermocopule, Thermister ressure Sensor / &orden Tube, &ellows, Strain gauge 1low / sensor / itot tube !evel, Conductivity, "ensity, h.. What is transmitter? A transmitter is an electronic device that is generally mounted in the field in closepro2imity to a sensor. The sensor 'also known as a transducer( measures a physicalvariablesuchastemperatureorpressureandoutputsaverylowlevel electronicsignal. The basic function of the transmitter is to provide the correct electrical powerto turn on 'or e2cite( the sensor then to read the low level sensor signal, amplify it toa higher levelelectrical signal and send that signala long distance to a controlorread3out device. Since low3level electrical signals do not transmit long distances with great accuracy,installing a transmitter generally gives a tremendous improvement in the accuracy ofthe informationdeliveredto alargercontrolsystem.Typically theoutput formthetransmitter is 4356 mA or 6376 81/. Why 402/ mA preferred o1er /01/ 2 si-nal? The 6376 8 signal has tendency to drop because of line resistance. #f the distancebetween sensor and input card is more the signal will not properly represent the fieldvalue. The 4356 mA will travel a long distance without dropping signal value. 11. Why 402/ mA preferred o1er /02/ mA si-nal? 9ith 6356 mA you can not distinguish between minimum field value and connectionbreak. 9ith 5356 mA, internal circuit can distinguish between connection break ofminimum value. :ormally when the value is minimum the transmitter will give you 4mA while in case of connection breakage it will give 6 mA. 12. eference !et#een 2 #ire3 3 #ire and 4 #ire transmitter. #n 5 wire transmitter the power and signal are transmitted through same cable. #n ; wire transmitter the data signal and power are with respect to common ground. #n 4 wire transmitter two wires for power supply and two for signals. $nly current transmitters can be used as 5 wire transmitters. 13. What is a 4)mart5 6ransmitter?A m 7.5 km 6.4AC >m ;6 km

Pro-ramma!le $o-ic %ontroller0 )iemens .3. What are the 1arious P$% system in )I