
Air Compressors produce compressed air. Commonly Reciprocating or Screw
Compressors are employed as the discharge pressure required for pneumatic application is in the
range of 6-8bar. Building real world reliable and robust systems nowadays is usually associated
to the use of Programmable Logic Controllers PLCs. These devices are modular digital
computers that allow using a large variety, and number, of electrical input and/or output
interfaces. The mechanical, hardware and software are designed to handle continuous operation
in environments overwhelmed with electromagnetic and mechanical noise. These characteristics
make PLCs ideal for usage within industrial environments with the recent advances in the world
of automation, especially in the industrial field; the use of modular digital computers has become
vital.
Most of the control elements used to execute the logic of the system was substituted by the PLC
Programmable Logic Controller; a program stored in the central unit of a computer determines
the execution of operations in function of the state of the controlled variables. The commands
written by an electronic programmer or by a microcomputer Sensors and switches are plugged as
inputs and the direct control valves for the actuators are plugged as outputs. An internal program
executes all the logic necessary to the sequence of the movements, simulates other components
like counter, timer and control the status of the system.
 Let’s draw its ladder diagram inside G M WIN software to do so first insert project file name
called cylinder control using a double-solenoid valve
Then make sure among the programing language it is ladder diagram then Finish.
You can get all of these instructions on the right hand side corner so select the tools among the
existing ones and complete the ladder diagram as you can see
We represent each of those input and output components as follows
PB1 means push button one whose digital input address is allocated at I X0.0.16, RETPOS
means the cylinders retracted position having a digital input allocation of I X 0.0.0, T not means
the on timer output address, MX 0 means the internal memory address, Y1 means the supply
cylinder coil tag which helps to advance the cylinder piston having a digital output address
QX0.0.0, ADVPOS means the advanced position of a cylinder digital input having address of I
X0.0.1.
PT- in the on timer means preset time so we need to set three second so place T hash tag 3s.
And Y2 means the stopper or blockage cylinder with its output address of QX0.0.1 is used as the
second solenoid valve to block any item the one which is pushed through the supply cylinder.
 Here three memory address MX0,MX1 AND MX2 are used
 ADVPOS is the advanced position sensor of a cylinder with an input address I X0.0.1
 After completing this ladder diagram compile the program so compiled successfully then go
to online connect write + run + monitor on then upload the program towards to the G M WIN
PLC module. As the status depict make completed and linkage is successful.
 We are able to see the ongoing process in a simulation manner on a serial monitor.
 As it is shown the push button is used to reset the up counter that resets the current value
of a counter to zero as it is pressed twice and so forth. After it reaches preset value and
try to exceed here for a counter we use three as a preset value. At last the supply cylinder
coil tag Y1 have given the output address of QX0.0.0
 so to trigger the coil tag of a cylinder piston the first memory address MX0 is needs to be
energized and the second memory address MX1 not needs to be energized meaning it
should stay in de energized state.
 There are two or double solenoid valves the first one is represented by Y1 which is the
supply solenoid piston with allocated address having QX0.0.0 and the second one is
designated by Y2 which is the stopper or blockage solenoid piston and its output pin is
connected with QX0.0.1.Well as the push button pressed once it helps to trigger the
supply cylinder piston and advance this will results in the stopper piston starts to activate
its piston to block anything supplied through the supply cylinder except either it returns
back the supply cylinder to its retracted position or the counter current value is equal to
preset value and turn off the system as a whole. To describe the principle of operation of
the ladder diagram line by line as the push button is operated for the first time the first
memory which is MX0 gets supply from the rang and self-hold its circuit now it is
independent of neither the cylinder piston is in retracted position nor the push button is
not pressed and the only thing that is left to activate the supply cylinder is MX0 which is
now made and it is energized so which changes the cylinder piston from retracted
position to advanced position this helps the second memory address MX1 coil tag gets
energy due to this reason the stopper or blockage cylinder activates and pushes its
cylinder downward on the other side it disrupts the supply cylinder piston activation so
that will tend to retract as a result the third memory address MX2 is the input for a
counter to count and as we see from the ladder diagram it depends up on the memory
address MX1 and the supply cylinders piston to be returned this is detected by retract
position sensor. This is achieved through when MX1 and retracted position sensor
detection senses those two important effects to be mate. And helps to detect those effects
and allows the supply cylinder piston on off three times in doing so the stopper or
blockage cylinder stays downward for any of supply cylinder activation even if it stays
downward a little bit it tries to return while its effect is negligible and due to in an
interlock manner connected normally closed set of contact of the up counter output that
results in to cease the overall program. So if the push button is pressed for the second
time it will results in two things the first one is to reset the counters current value to zero
and the second one would repeat the previously expressed execution.
Thank you very much
And don’t forget to subscribe and share the video if you find it helpful.
Stay creative.
This is PRD-SS Channel