KNOWARE  

Software for Education and Industry


PLC Ladder Logic

and Function Blocks

with

CODESYS V3.5

Want to learn how to program a PLC in Ladder Logic and Function Block Diagrams, make HMIs (Human Machine Interfaces) and be able to run your programs on a simulated PLC?  PLC Ladder Logic and Function Blocks with CODESYS V3.5  shows you step-by-step how to program a PLC using free CODESYS software.

Simply download the free CODESYS software at http://store.codesys.com/codesys.html?___store=en&___from_store=default then follow the exercises in PLC Ladder Logic and Function Blocks with CODESYS V3.5 to learn how to program in Ladder Logic and Function Block Diagrams, build HMIs, and run your programs on a simulated PLC. You do not need an actual PLC to use PLC Ladder Logic and Function Blocks with CODESYS V3.5.

PLC Ladder Logic and Function Blocks with CODESYS V3.5 is written in everyday, easy to understand language that shows you step-by-step what to do.  PLC Ladder Logic and Function Blocks with CODESYS V3.5 is written in .html format so you can use your favorite internet browser with hyperlinks, bookmarks, and word searches.  PLC Ladder Logic and Function Blocks with CODESYS V3.5 requires no software installation on your computer.  Just double click on the Table of Contents.html, and your Internet browser launches the program.

What is CODESYS?
CODESYS is a program written by the German company 3S-Smart Software Solutions to program various PLCs. It is written to conform to IEC 61131-3, an open international standard for PLC programming languages.  Another program similar to CODESYS called TwinCAT 3 was developed by the German company Beckhoff.  CODESYS has a built-in simulation PLC, built-in HMI capability (Human Machine Interface or Visualization), and can be programmed in various PLC languages, including:
Who uses CODESYS?
CODESYS is used by companies such as Bosch, ABB, Moeller, Wago, Eaton, Festo and others to program their PLCs.

What
PLC Ladder Logic and Function Blocks with CODESYS V3.5 does:
This tutorial will show you step-by-step:

What PLC Ladder Logic and Function Blocks with CODESYS V3.5 does NOT do:
This tutorial does not address:

No prior knowledge of PLCs is necessary.

This tutorial is written by a Professional Engineer with 14 years industrial experience and 20 years experience teaching electrical engineering technology at the college level.

If you want to learn how to use CODESYS to program PLC Structured Text programs, you can purchase my PLC Structured Text with CODESYS V3.5 tutorial at http://www.knoware-online.com/st_codesys.html. Or if you want to learn how to use CODESYS to program PLC Instruction List, you can purchase my PLC Instruction List with CODESYS V3.5 tutorial at http://www.knoware-online.com/il_codesys.html.

If you want to run and solve Ladder Logic programs without using CODESYS you can purchase my PLC Simulator 10 at http://www.knoware-online.com/pc-plc.html. This simulator turns your PC into a PLC, has the "look and feel" of Allen-Bradley RSLogix Micro software (though not exact), runs and solves Ladder Logic programs that you write, and allows you to build machines with limit switches, pilot lights, selector switches, solenoids, and conveyors that move in response to the ladder programs you write.   

How to use this tutorial:
To use this tutorial, download a free copy of CODESYS at http://store.codesys.com/codesys.html?___store=en&___from_store=default, then perform the exercises in Chapters 1 through 13 of this tutorial.   This tutorial can be used without downloading CODESYS, but the benefit of hands-on programming experience will be lost.

Chapters 1 though 5 of this tutorial explain how to download CODESYS, install it, program a rung, build an HMI, and run the program.

Chapters 6 thru 13 move at a little faster pace and explain many of the more advanced function blocks of CODESYS.



PLC Ladder Logic
and Function Blocks
 with
CODESYS V3.5

Table of Contents

              Chapter

              1.  Introduction
                        What is a PLC?           
                        History of PLCs

                        What is CODESYS?
                        Who uses CODESYS?

                        What this program does
                        How to use this program

                        What you need to use this program

                       

              2.  Launching CODESYS

                        Download CODESYS

                        Start CODESYS
                        Start a New Project
                            
Save the Project
                        Summary                        

                     

              3.  Programming Your First Rung

                        Open the Project Created in Chapter 2

                        Open PLC_PRG
                        Insert a Contact
                        Insert a Coil
                        Insert a Rung Comment
                        View as a FBD

                        Save the Project

                              Summary                                   

              4.  Creating an HMI

                        Open the Project Saved in Chapter 3
                        Create an HMI
                        Program a Dip Switch
                        Program a Lamp
                        Save the Project
                        Summary


              5.  Running Your Program

                        Open the Project Saved in Chapter 4
                        Choose the Simulation PLC
                        Build (compile) the Program
                        Login to the Simulation PLC
                        Start the PLC

                        Close the Switch from the HMI

                        Close the Switch by Forcing It
                        Stop the PLC
                        Logout from the PLC
                        Save the Project

                        Summary                 
            


                6.  Latch and Unlatch Relays (Set, Reset)

                        Start a New Project

                        Program a Set Coil             
                        Program a Reset Coil
                        Create an HMI
                        Run the Program

                        Program an SR and RS Function Block
                        View as a FBD

                        Save the Project
                        Summary

                7.  Timers (TON, TOF, TP)

                        Start a New Project
                        Program a TON Timer
                        Program PT and ET
                        Program TON Timer Contacts
                        Run the TON Program
                        Program a TOF Timer
                        Run the TOF Program
                        Program a TP Timer
                        Run the TP Program
                        View as a FBD

                        Save the Project
                        Summary

              

               8.  Counters (CTU, CTD, CTUD)

                        Start a New Project
                        Program a CTU Counter
                        Program a CTU HMI
                        Run the CTU Program
                        Program a CTD Counter
                        Program a CTD HMI
                        Run the CTD Program

                        Program a CTUD Counter
                        Program a CTUD HMI
                        Run the CTUD Program
                        View as a FBD

                        Save the Project
                        Summary

              

                9.  Jumps and Subroutines

                        Start a New Project
                        Program a Jump and Label
                        Run the Jump and Label Program
                        Create a new POU
                        Program the new POU
                        Program a Visualization
                        Run the Jump to Subroutine Program
                       
Change the Main Task
                        View as a FBD
                        Save the Project
                        Summary
             

             10. Boolean Operators (AND, OR, XOR, MOVE)
                        Start a New Project
                        Program an AND Condition
                        What if the Inputs are Numbers?
                        AND two Decimal Numbers
                       
AND two Binary Numbers
                        AND two Hex Numbers
                        AND two Octal Numbers

                        AND two Variables

                        Program an OR Condition
                        Program an XOR Condition
                        Save the Project
                        Summary

            11.  Math Operators (ADD, SUB, MUL, DIV, MOD)

                        Start a New Project
                        Program an ADD Function
                        Program an SUB Function
                        Program an MUL Function
                       
Program an DIV Function
                        Program an MOD Function
                        Change the Variables to Type REAL

                        Save the Project
                        Summary 

            

            12.  Compare Operators (EQ, NE, LT, LE, GT, GE)

                       Start a New Project
                       Program a EQ Function
                       Program a NE Function
                       Program a LT Function
                      
Program a LE Function
                       Program a GT Function
                       Program a GE Function

                       Save the Project
                       Summary

                       

            

           13  Selection Operators (SEL, MUX, MIN, MAX, LIMIT)

                      Start a New Project
                       Program an SEL Function
                       Program a MUX Function
                       Program a MIN Function
                      
Program a MAX Function
                       Program a LIMIT Function
                       Save the Project
                       Summary

 

                    

            Index

 

Sample excerpt from... 

 Chapter 13.  Selection Operators (SEL, MUX, MIN, MAX, LIMIT)

 

Step 3)  Program a MUX Function

Insert a rung after rung 3 and Assign the value of 4 to Input4 as shown in Figure 3 below.  Make Input4 be Type REAL.

Figure 3  Adding an Input 4

Adding Input 4

Add new rungs 6 and 7 as shown in Figure 4 below.  Program an up counter (CTU) in rung 6 and a multiplexer  (MUX) in rung 7.  We will use the counter to step the multiplexer. Enter 3 at the PV value of the counter. Add two additional inputs to the MUX by right clicking it then choosing Append Input (do this twice). Program CTR1.CV at the K input of the MUX, and Input1 thru Input4 at the other inputs.  Program Result1 as the output variable for the MUX and make it Type REAL.  All inputs, except K, and the output must be of the same data Type for the MUX. Your screen should look like Figure 4 below.

Figure 4  Adding a CTU and MUX

Add a CTU and MUX

A MUX function is like a selector switch with multiple positions.  The K input determines which Input will get through to the output.  When K = 0, the top Input gets through to the output of the MUX, when K = 1, the next Input gets through, and so forth.  Figure 5 below shows the MUX function as a selector switch.

Figure 5  MUX as a Selector Switch

MUX as a selector switch

Run the program.  See Chapter 5 if you need a refresher on running a program. The CV (current count) of  counter CTR1 should be 0 starting out.  If it is not 0, click on Online>>Reset Cold, then start the PLC again. Notice that K is 0 on the MUX because the K input is CTR1.CV, so Input1 is getting through to the MUX output.

Hardware/Software Requirements:

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