0:07
in this video I will discuss about live
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Advantage this is the solution to the
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problem I will consider 4
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to20 Milam as a range and we already
0:28
know four represents 0% of the scale and
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20 represents 100% of the
0:39
okay now I'll go to the same
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consider level transmitter range is 4 to
0:52
milliamp now the tank level is 0
0:56
percentage so I will update the table
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zero and transmitter sends 4 milliamp to
1:09
PLC so transmitter output is four and
1:15
four and computer receives 0% level from
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the PLC so computer is
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zero let's say due to some reason the
1:32
circuit there may be a open
1:38
failure any reason something happened
1:56
broken now we will see what happens to
2:03
readings the tank level is 0
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percentage the level transmitter status
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milliamp okay because the tank level is
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so the 4 milliamp it will not reach the
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PLC so PLC receives zero instead of
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four see the PLC receiving 0
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milliamp so what happens here is the PLC
2:43
already knows that the minimum value it
2:49
milliamp per 0% process
2:53
variable when the tank level is zero it
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already knows that it receives 4 million
3:00
a but right now it is receiving 0
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milliamp so it will cross check it will
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comparison that the minimum value I need
3:16
milliamp as I am receiving less than 4
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PLC identifies this milliamp
3:30
this 0 milliamp as quy
3:35
state okay then it will update the
3:39
computer that this transmitter is in
3:42
faulty state do not consider the
3:47
readings so it will not update the
3:49
readings instead it will update the
3:52
status of the transmitter that there is
3:56
problem there is a fault that is why the
4:00
computer status is faulty
4:03
State okay faulty State for the level
4:09
transmitter there may be a problem
4:11
between anywhere there may be a problem
4:13
with broken wire or some short circuit
4:17
or there is a sensor failure damage or
4:20
some other reason whatever the problem
4:24
is the PLC display it as a common fault
4:31
okay the PLC compares the base line the
4:36
base line is 4 milliamp it must receive
4:42
four so when we use this 4 milliamp as a
4:45
starting range we can solve the dead
4:51
problem right now the tank level is
4:54
empty still we are identifying the issue
4:57
the PLC identifies the issue and updates
5:02
computer then what happens the operator
5:06
sees this faulty State then immediately
5:11
informs to the maintenance
5:13
person they will carry out the
5:17
troubleshooting let's say the tank level
5:21
50% okay the tank level is
5:28
50% the level transmitter sending 12
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PLC but the wire is still
5:37
broken level transmitter sending 12
5:40
milliamp as wire is broken how much the
5:45
receives zero it will not receive any
5:49
current so the PLC receives zero again
5:54
same concept it must receive
5:57
four if it is receiving less than for
6:04
immediately it will consider the state
6:11
faulty in this way when we have live
6:15
zero that means we have to use some
6:20
value instead of zero we must use some
6:27
number when you use some number as a
6:30
starting range then we can easily
6:37
fault we can avoid the dead zero
6:43
problem now we understand the
6:47
concept but there is one
6:55
question here in this example
6:59
we taken 4 to 20 milliamp as a
7:04
range let's suppose the range is 6 to 20
7:09
milliamp in this case also we have live
7:19
means the live zero Advantage will be
7:22
applied to any number not only four we
7:27
can take 3 to 20 milliamp as a a range
7:31
we can take 6 to 25 mamp as a
7:35
range in the next upcoming videos we
7:38
will discuss clearly why the four is
7:42
selected now in this video we understand
7:46
that we must at any case we must not
7:50
select zero as a starting range if you
7:53
select zero the PLC will unable to
7:59
okay so to identify the dead zero
8:02
problem we must use some value it may be
8:05
a 1 milliamp it may be a 2 mamp it may
8:09
be a 3 milliamp any value it is fine the
8:13
live zero Advantage will be
8:18
okay in this case the L Advantage
8:24
milliamp at the same time it will apply
8:27
to any other number also
8:32
okay I will meet you in the next video
