Single acting pneumatic cylinder operation using 3/2 direction control valve.

Problem Description: -

The operation of Single acting pneumatic cylinder by using two pushbuttons PB1 and PB2. PB1 is for start the operation and PB2 is for stop the operation.

Diagram: -

Here we took Single acting cylinder and 3/2 single solenoid spring return valve now we have to use electric circuit to operate solenoid.

 

Program: -

Here is PLC program for making START/STOP pneumatic cylinder operation using PLC.

 

List of Inputs/Outputs

List of Inputs

X0: -PB1

X1: -PB2

List of Outputs

Y0: -Cylinder Relay output

Ladder Diagram for single acting pneumatic cylinder operation using 3/2 direction control valve.

Program Description: -

-In the ladder diagram, we use two push button one for start (PB1) and other one to stop (PB2). And we also use relay for operate solenoid as shown in figure.

-We give direct 24 voltage to PB1 (NO) and then PB1 normally open contact to PB2 (NC) and then PB2 normally closed contact to the relay.

-Now we take one normally open contact of relay and give to the PB2 common to give continuous supply to the relay it is called latching and take second normally open contact of relay to the solenoid and give 0v to solenoid to complete circuit.

-Now when we press PB1 power supply to the relay and relay start. And by starting relay solenoid is also get power and operate valve. Now if we release PB1 but power to the solenoid will not stop because of latching.

-Now when we press PB2 contact will open stop the relay that’s why solenoid is also stop and cylinder will back at their normal position because of spring return valve.

                                                                                    By Mansuri Afnan

Sequential lamps operation using PLC

This is a PLC program for the sequential lamp operation.

Problem description: -

Write PLC program to operate lamps in sequential mode using ladder diagram Language.

 Problem diagram: -

Solution: -

Here in this system, there are two lamps, two bush buttons which are connected to the PLC.

 The bush buttons are connected to the PLC inputs and lamps are connected to the Outputs of the PLC.

There are following condition for the system to work which are as follows: -

1)    When START PB is to be pushed lamp1 should start and lamp 2 should start after 5 seconds of lamp1.

2)    When STOP PB is to be pushed both the lamps1&2 are to be stopped.

 Now to meet the following conditions we have use a timer which delay the operation of lamp2. 

List of inputs/outputs: -

Inputs: -

1)     X0 -Start PB

2)     X1 -Stop PB

Outputs: -

1)     Y0 -Lamp1

2)     Y1 -Lamp2

Ladder diagram for the sequential operation of the lamps.

Program Description: -

-In Rung we used STRAT PB (X0) to start LAMP 1 (Y0). Here we used NC contact of STOP PB (X1) to stop the LAMP 1(Y0). In parallel of X0 contact we used NC contact of Y0 to latch the output.

-In second rung we used Timer T1 to count the delay for the LAMP 2 (Y1).

-In rung 3 we used NO contact of T1 so once time delay over the LAMP 2 (Y1) will on.

 

                                                                                              By Naisarg Prajapati

Double acting Cylinder Forword/reverse operation using PLC.

 Double acting Cylinder Forword/reverse operation using PLC.           

This is the PLC program for double acting cylinder operation using PLC.                                                              

Although writing a PLC program in Double acting cylinder is a highly technical process, it can be understood in simple language:

Problem Description: -

We need to operate double acting cylinder using PLC. Write the PLC program using ladder diagram language and draw pneumatic circuit.

 

Problem Diagram: -

Solution: -

Here we need to operate double acting cylinder with PLC. As show in figure we took two push buttons for forward and reverse operation. PLC is used to control the outputs. We used double solenoid direction control valve for forward and reverse operation of the cylinder. Once user will press forward button, cylinder will move forward and if user presses reverse button, cylinder will move reverse.

Here we used PLC for output control so need to write program in PLC according to application.

 Program

Here is PLC program for making forward/reverse cylinder operation using PLC.

 

List of Inputs/Outputs

List of Inputs

X0: -Cylinder Forward

X1: -Cylinder Reverse

List of Outputs

Y0: -Cylinder Forword

Y1: -Cylinder Reverse

 

Ladder Diagram for forward/reverse operation of double acting cylinder.

Program Description: -

-        In first rung we have used NO contact of the Cylinder forward push button (X0) so Cylinder forward (Y0) output can be operated with the forward push button (X0).

-        In first rung we have used NO contact of the Cylinder reverse push button (X1) so Cylinder reverse (Y1) output can be operated with the reverse push button (X1).

Making application to move block from the magazine feeder to conveyor using pneumatic system.

Making application to move block from the magazine feeder to conveyor using pneumatic system.

Problem Description: - There is one conveyor system. Single acting cylinder should start if user press bush button and block should move form magazine feeder to conveyor system for next process. 

Problem Diagram: -

Solution: -

Here we can consider single acting cylinder, take one spring return bush button to operate singly acting cylinder. Push button will work as 3/2 bush button valve. If bush button is pressed, cylinder will operate and move the block and if it is released, cylinder will back to its original position. 

Pneumatic circuit: - 

Pneumatic circuit explanation: -

Here we can see in the figure single acting cylinder with spring return. It can push block when required and it can come back with spring force if bush button released. Connect pneumatic pipe from A to cylinder in as shown in figure.

We took 3/2 bush button so in normal condition air will pass from A to R as shown in figure, so cylinder is in normal condition. If we press push button, air will pass from P to A so cylinder will move. Connect Main air line in Port P of the 3/2 push button.

If we release push button air will not pass from P to A so due to spring force it will come back.

 

Conveyors sequence operation

This is PLC Program for controlling conveyors ON sequence and OFF sequence.

 

Problem Description:-

There are three belt conveyor in the system. We need to control sequences of conveyors both ON sequence and OFF sequence. Implement logic in PLC using ladder diagram programming language.

 

Problem Diagram

 

Problem Solution.

We will use PLC S7-300 for this application. Also we will use TIA portal software for programming.

Conveyor belt 1 or conveyor belt 2 can be started by the corresponding START pushbuttons and can be stopped by corresponding STOP push buttons.

Conveyor belt 3 should always transport when either conveyor belt 1or conveyor belt 2 is transporting.

When OFF pushbutton is pressed, belt 1 or belt 2 is to continue running for 20 sec. and belt 3 for 60 seconds to clear the belts of material and Then stopped.      

 

There is 10 Hz. monitoring signal for belt status monitoring for all three belts. If there is fault in any one of the belts then the entire belt should turn off immediately.

 

 And OFF indications of previously running belts should flash with 5 HZ frequency.

 

Program

Here is PLC program for controlling conveyors ON sequence and OFF sequence.

List of inputs/outputs

List of inputs

System ON/OFF switch:-I2.0

Belt 1 START:-I0.0

Belt 1 STOP:-I0.1

Belt 2 START:-I0.2

Belt 2 STOP:-I0.3

Belt 1 fault:-I1.0

Belt 2 fault:-1.1

Belt 3 fault:-I1.2

List of outputs

Conveyor belt 1:-Q0.0

Conveyor belt 2:- Q0.1

Conveyor belt 3:-Q0.2

Belts running indication:-Q0.3

Fault indication:-Q0.4

Fan 3 ON Indication:- Q0.6

Main supply ON indication:-Q0.7

M memory:-

Cycle ON:-M0.0

5HZ clock pulse:-M0.5

10HZ clock pulse:-M1.0

 

Ladder diagram for controlling conveyors ON sequence and OFF sequence.

 

 

 

Program Description

For this application we used S7-300 PLC and TIA portal software for programming.

Network 1:-When system ON switch (I2.0) is pressed, cycle ON (M0.0) bit will be ON.

Network 2:-When belt 1 START PB (I0.0) is pressed, Conveyor belt 1(Q0.0) will be ON.

Network 3:- When conveyor belt 1 STOP button (I0.1) is pressed, timer will start to count time and after 20s timer will stop the conveyor belt 1 (Q0.0). If fault occur in conveyor belt 1, belt 1 should be STOP.

Network 4:-When belt 2 START PB (I0.2) is pressed, conveyor belt 2 (Q0.1) will be ON.

Network 5:- When conveyor belt 2 STOP button (I0.3) is pressed, timer will start to count time and after 20s timer will stop the conveyor belt 2 (Q0.1). If fault occur in conveyor belt 2, belt 2 should be STOP.

Network 6:-Either conveyor belt 1 (Q0.0) or conveyor belt 2 (Q0.1) is ON, Conveyor belt 3 (Q0.2) will be ON. If fault occur in conveyor belt 3, it should be STOP.

Network 6:-When both conveyors are OFF, Conveyor 3 off timer will be executed.

Network 7:-When conveyor belt 3 timer is executed, after 30s it will stop the conveyor belt 3 (Q0.2).

Network 8:-Either conveyor belt 1 STOP PB (I0.1) or conveyor belt 2 STOP PB (I0.3) is pressed, conveyor 1&2 reset timer will be executed.

Network 9:-If three conveyors are running in healthy condition, belts running indication lamp (Q0.3) blinks on 10HZ frequency.

Network 10:-If any conveyor belt is faulty out of three belts, fault indication lamp (Q0.7) will start to blink on 5HZ frequency.

Note:-Above application may be different from actual application. This example is only for explanation purpose only. We can implement this logic in other PLC also. This is the simple concept of conveyor ON and conveyor OFF sequence in industry, we can use this concept in other examples also.

All parameters considered in example are for explanation purpose only, parameters may be different in actual applications. Also all interlocks are not considered in the application.

 

Runtime Test Cases

Inputs	Outputs	Physical Elements
I2.0=1	M0.0=1,Q0.7=1	Cycle ON, main supply On indication lamp ON
I0.0=1	Q0.0=1	Conveyor belt 1 ON
I0.2=1	Q0.1=1	Conveyor belt 2 ON
Q0.0=1or Q0.1=1	Q0.2=1	Conveyor belt 3 ON
I1.0=1orI1.1=1orI1.2=1	Q0.4=1	Fault indication lamp ON