Draw the flow chart of any industrial application and implement it using Ladder Logic.

1. Zunaib Ali - 09 Muqadsa Iftikhar - 03
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Lab Report No: 11
Programmable Logic Control (PLC)
Apparatus:
 Internet Activated PC.
Theory:
Every system or machine has a controller. Depending on the type of technology used,
controllers can be divided into pneumatic, hydraulic, electrical and electronic controllers.
Frequently, a combination of different technologies is used. Furthermore, differentiation is
made between hard-wired programmable (e.g. wiring of electro-mechanical or electronic
components) and programmable logic controllers. The first is used primarily in cases, where
any reprogramming by the user is out of the question and the job size warrants the
development of a special controller. Typical applications for such controllers can be found in
automatic washing machines, video cameras, and cars. However, if the job size does not
warrant the development of a special controller or if the user is to have the facility of making
simple or independent program changes, or of setting timers and counters, then the use of a
universal controller, where the program is written to an electronic memory, is the preferred
option. The PLC represents such a universal controller. It can be used for different
applications and, via the program installed in its memory, provides the user with a simple
means of changing extending and optimizing control processes. The original task of a PLC
involved the interconnection of input signals according to a specified program and, if "true",
to switch the corresponding output. Boolean algebra forms the mathematical basis for this
operation, which recognizes precisely two defined statuses of one variable: "0"and "1.
PLC has evolved as an important controller in industries these days because of its simplicity
and robustness. It is used for controlling many mechanical movements of the heavy machines
or to control the voltage and frequency of the power supplies.
The applications include the
Continuous bottle filling system,
Batch-mixing system,
Speed control of dc motor,
3 stage air conditioning system,
Control of planar machine and
The automatic frequency control of the supply, during induction heating.

2. Zunaib Ali - 09 Muqadsa Iftikhar - 03
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LAB TASK:
Draw the flow chart of any industrial application and implement it using Ladder Logic.
Application:
Continuous Bottle Filling System
This is one of the important application of PLC in the bottle filling industry where we want
our bottles, which are moving on the conveyor belt, to be automatically detected at the
appropriate position and get it filled by any desired liquid and also after getting filled the
queued bottle gets chance to be filled. If this whole process is carried out manually it will
really take a long time and also the quantities will be quite lesser. So PLC becomes requisite
controller for these types of industry.
Objective-
We will implement a control program that detects the position of a bottle via a limit switch then
waits for 0.5 secs, and then fills the bottle until a photo detector detects the filled condition of the
bottle. After the bottle is filled, the buzzer sounds and the control program will again wait for
0.7secs, before moving to the next bottle. Until the limit switch signals, the feed motor, M1 runs
while there are fixed rollers which carries the filled bottles. Motor, M2 keeps running after the
process has been started.
Fig. 1: Automatic Bottle Filling System

3. Zunaib Ali - 09 Muqadsa Iftikhar - 03
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Flow Chart-
Start
Turn-ON Light (L1)
Start Outfeed Motor (M2)
LS Signaled
Stop feed Motor (M1)
Start Solenoid Valve (S1) after
0.5sec
Start feed Motor (M1)
Yes
No
PE Signaled
Turn-ON Buzzer (B1)
Stop Solenoid Valve (S1)
Yes
Turn-ON FB after a delay of
0.7sec
No
Fig.2: Automatic Bottle Filling System Flow Chart

4. Zunaib Ali - 09 Muqadsa Iftikhar - 03
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Ladder Logic-

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Inputs and Outputs Used-
Observation-
Once the start button is pressed the green light (L1) turns ON and remains ON until stop
button is pressed. As light turns ON outfeed motor (M2) starts running. After M2 runs and if
either limit switch (LS) has not signaled or filled bottle condition is fulfilled motor (M1)
starts. After limit switch has signaled timer, T1 gets activated. After T1 gives done (DN)
signal and photoeye detector (PE) is disabled, solenoid valve gets in operation. As PE signals
solenoid stops and buzzer (B1) sounds after which timer, T2 gets enabled which stops the
process for 0.7 seconds. Once the filled bottle condition is activated the cycle starts again.
The ladder diagram was successfully checked in the GMWIN and all the prescribed
conditions were observed completely.

6. Zunaib Ali - 09 Muqadsa Iftikhar - 03
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Simulations-
When Start Button is pressed Light L1, Motor M2 and Motor M1 gets On/Started.
When Limit Switch is signaled Motor M1 is stopped and Solenoid Valve S1 is turned-
ON.

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When photoeye detector is signaled, Solenoid valve is turned-OFF, and after some
time Filled Bottle signal is made high and process is repeated again and new bottle is
filled.