System and Communication

8/11/2019 System and Communication

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Computers in control computer studies [email protected]

Control and Monitoring system

Monitoring system

Example:

monitoring patients vital signs(uses oxygen, brain activity sensor)

Weather forecasting

(uses temperature, pressure sensor)

o! monitoring system !or"s

#$ Computer continuously collect data from sensors$

%$ &ata is converted using analogue to digital converter ('&C) to enable computer tounderstand and process the data$

*$ Computer compare new data!ith stored data$

4. if there is a big change between new data and stored data, computer system will warn

user in form of sound (e.g. alarm, siren or beeping sound).

Example:

Example:

ospital monitoring:

stored data(normal oxygen) is + - #..$

/f new data(collected from patient) is 00, it should give out alarm$

Control system

Examples:

traffic lights (controlling se1uence of lights to maintain optimum traffic flo!)

uses pressure sensor

Chemical and nuclear plant (open and close gas valves)

uses gas sensor

o! control system !or"s:

#$ Computer continuously collect data from sensors$


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%$ &ata is converted using analogue to digital converter ('&C) to enable computer to

understand and process the data$

*$ Computer compare new data!ith stored data$

4. Computer system will send signal to device and change the data back to analogue usingDC (digital to analogue converter).

!. "nstruct device to switch on or off.

Example

2raffic control system:

stored data(normal car 1ueue) is %.$

/f new data(collected from north sensor) is 3., and (collected from south sensor) is #.,

it should instruct south light to turn green first$

'dvantages:

Safer (faster response and computer dont get tired and miss key data) Computer work 24/ !ore accurate and can take more fre"uent readings (#f reading need to

$e taken e%ery &' seconds uman may miss it)

control and monitoring system, control system,monitoring system, 2ypes of 4ystem

5et!or" system

3$* 2ypes of 4ystem - 5et!or" 4ystem

3$*$# /ntroduction5et!or" is a group of computers lin"ed together$

3$*$% 'dvantages and disadvantages of net!or"'dvantages of net!or":
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6eripherals (e$g$ printers) can be shared$

4oft!are can be shared$

&ata can be shared$

Computers may communicate

4ecurity - user access may be restricted if needed

&isadvantages of net!or":

7ne server brea"ing do!n may affect a number of computer

8ulnerable to hac"ers and viruses

Cabling and installation may be expensive

' net!or" manager may need to be employed to run the net!or"

3$*$* 2ypes of net!or":' 9ocal 'rea 5et!or" (9'5) - computers are on the same site building and lin"ed by cables$

4ome 9'5 no! uses !ireless lin"s$

' Wide 'rea 5et!or" (W'5) - computers are on different site and are lin"ed by telephone

lin"s$ ' computer may need to use a modem to lin" to the telephone system$ ' W'5 can cover a

!hole country or even the !orld$

#ardware re$uired to set up network%

Cables

4!itch or router5et!or" card

Modem (for W'5)

&'tra information6eer;to;peer net!or"s

- all computers are of e1ual importance$4oft!are and data are stored on each computer$

Clientserver net!or"s

- soft!are and data are held on a file server and may be used by other computers on the net!or"$

4ecurity is controlled centrally$


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3$*$< 5et!or" 2opologies

=our types of net!or" topology are briefly described here$>ing net!or"s::::

Comments#$ a faulty connection bet!een t!o stations can cause net!or" failure

%$ it is difficult to add a ne! stationdevice as it has to come bet!een % existing stations

*$ this type !or"s !ell during heavy loading


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net!or" system, ring, star,topology, tree, 2ypes of 4ystem

4ingle user online system

2here are t!o types of single user operating system:

a) 4ingle user, single tas"b) 4ingle user, multi tas"

A7nline system simply means that the user is connected to the processor$

a) ingleuser, single task

's the name implies, this operating system is designed to manage the computer so that one user

can effectively do one thing at a time$ 2he 6alm 74 for 6alm handheld computers is a goodexample of a modern single;user, single;tas" operating system$

b) ingleuser, multitasking

2his is the type of operating system most people use on their des"top and laptop computers

today$ Microsofts Windo!s and 'pples Mac74 platforms are both examples of operating

systems that !ill let a single user have several programs in operation at the same time$ =orexample, its entirely possible for a Windo!s user to be !riting a note in a !ord processor !hile

do!nloading a file from the /nternet !hile printing the text of an e;mail message$

Multi;users online system

2his system allo!s more than one person to use the same computer at the same time$ 2heprocessor is so fast that !e thin"s that !e are online all the time$ /n fact, each terminal is given

some time on the processor, before it moves on to the next terminal$

image from: http:bcis$pacificu$eduBournal%..0.%imagesthinclient$png

'c"no!ledge to:

http:computer$ho!stuff!or"s$comoperating;system*$htm
http://syeqahz.wordpress.com/tag/network-system/http://syeqahz.wordpress.com/tag/ring/http://syeqahz.wordpress.com/tag/star/http://syeqahz.wordpress.com/tag/topology/http://syeqahz.wordpress.com/tag/topology/http://syeqahz.wordpress.com/tag/tree/http://syeqahz.wordpress.com/tag/types-of-system/http://computer.howstuffworks.com/operating-system3.htmhttp://syeqahz.files.wordpress.com/2011/05/thinclient.pnghttp://syeqahz.wordpress.com/tag/network-system/http://syeqahz.wordpress.com/tag/ring/http://syeqahz.wordpress.com/tag/star/http://syeqahz.wordpress.com/tag/topology/http://syeqahz.wordpress.com/tag/tree/http://syeqahz.wordpress.com/tag/types-of-system/http://computer.howstuffworks.com/operating-system3.htm


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*. customer/tra%el agent contacts te airline2. te customer/tra%el agents types in te day/time of igt and

num$er of tra%ellers&. te customer/tra%el agent types in te departure airport and te

destination airport

4. te airline data$ase is searced and a%aila$ility of seats cecked. if seats are a%aila$le on te re"uired day/time ten a $ooking is

made5. te data$ase/6le is updated immediately to indicate tat tese

seats are no longer a%aila$le and pre%ents dou$le $ooking fromoccurring

. if no seats are a%aila$le a message is sent $ack to tecustomer/tra%el agent

tis uses real time (transaction) processing since te 6les are updated in real

time7 interrogation of 6les will a%e access to totally updated information.(8,9:3 te a$o%e is sometimes referred to aspseudo real time since some

applications dont need immediate updating of te 6les)

+eal time process control

;rocess control is a real time system. ll

input data from recei%ed from sensors are immediately processed analysed

and immediately act on.

#t is usually used in industry to control and monitor macines. :ample3 igt

simulator. >s soon as computer recei%es data from mo%ed rudder te

?airplane responds.
http://syeqahz.files.wordpress.com/2011/05/online-booking-airline-copy.jpg


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http://syeqahz.files.wordpress.com/2011/05/flightsim2.jpg

System and Communication

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