Difference between revisions of "OpenPLC-version1-with-LDmicro/C3/Arithmetic-Instructions/English"

• Arithmetic instructions

• Arithmetic instructions

• Ubuntu 18.04 operating system
• LDmicro

• Ubuntu Linux 18.04 operating system
• LDmicro

• Working of One Shot instructions
• If not, please refer to the relevant tutorials from Home | spoken-tutorial.org

• To follow this tutorial, you should know the working One Shot instructions.

• If not, please refer to the relevant tutorials in this series on this website.

• Four arithmetic instructions

1. ADD
2. SUB
3. MUL
4. DIV

They are Add, Subtract, Multiply and Divide.

• Can only handle 16-bit signed integer values
• Floating point numbers are not handled by these instructions

Floating point numbers are not handled by these instructions.

Next to the right of it insert an ADD instruction as shown.

A dialog box opens which has three inputs.

Enter ‘result’

It should be the variable name to which you want to save the result.

Enter the variable name as ‘result’.

Type 4 in ‘is set to :=’ column

Type 5 in ‘+:’ column

Click OK button

These can be either constants or variables.

Enter the operands as 4 and 5 respectively.

Click on the OK button.

Also we can observe that there is no prefix before its name.

We will learn about these variables in the later tutorials.

Click Simulate -> Real-time simulation

For that, click Simulate and then on Simulation mode.

Next, start real-time simulation as shown.

For that, click Simulate and then on Halt Simulation.

Then click Simulate and Simulation Mode.

Click the OK button.

Click the OK button

It says ‘Constant 40000 out of range: -32768 to 32767 inclusive’.

This means that operands should be signed 16-bit integers.

Click the OK button.

Click Simulate -> Real-time simulation

Highlight the state of the ‘result’

And then again to 1.

We can observe that the state of the variable ‘result’ doesn't change.

Also, we will understand the importance of One shot instructions.

Change the second operand to variable ‘result’.

Click Simulate -> Real-time simulation

We can do that by using a One Shot instruction.

We can do that by using a One Shot instruction.

Click Simulate -> Real-time simulation

That is, ADD operation happens only once.

Change the state of Xswitch back to 0.

We can observe that the state of the 'result' changes to 8.

That is, ADD operation happens only when input changes its state from low to high.

Replace an OSF in the place of OSR. Observe the ‘result’ variable.

Observation:

The value changes when the input goes from high to low.

That is when the state of Xswitch goes from 1 to 0.

Replace an OSF in the place of OSR and observe the ‘result’ variable.

Observation:

The value changes when the input goes from high to low.

That is when the state of Xswitch goes from 1 to 0.

• Use OSR, when you want the change in count to happen when the switch is pressed
• Use OSF, when you want the change to happen when the switch is released

• Use OSR, when you want the change in count to happen when the switch is pressed
• Use OSF, when you want the change to happen when the switch is released

• SUB, MUL and DIV work similar to ADD
• NOTE: DIV instruction gives quotient as the result
• Explore these instructions on your own.

Note that the Divide instruction gives quotient as the result.

Explore these instructions on your own.

Let us summarize.

• Arithmetic instructions

• Arithmetic instructions

About Spoken Tutorial project

Please download and watch it

Spoken Tutorial workshops

• conducts workshops using spoken tutorials and
• gives certificates on passing online tests.

For more details, please write to us

Forum for specific questions:

Forum for specific questions:

Please visit the FOSSEE forum and post your question.

Acknowledgement

Thank you slide

And this is Harsha Priyanka from FOSSEE team, signing off.

Thanks for watching.