System Service of TwinCAT The TwinCAT System Service is represented by the TwinCAT icon in the Windows system tray.

The TwinCAT System Service can be accessed through the TwinCAT icon in the windows system tray (Right-Click and Left-Click provides the same menu)

From this menu the other parts of the TwinCAT system can be accessed and the TwinCAT System Properties can be changed

System Manager The TwinCAT System Manager is used to configure the links between Hardware and Software

I/O Configuration All Fieldbus Hardware

PLC Configuration PLC Run-Times (up to 4)

NC Configuration Axes (real and virtual), Cam Tables, Interpolation Channels

System Configuration Properties of the Target System and Real-Time Usage

Menus and Controls

File Menu Allows for creating a new file or opening a saved file.

In addition, it provides a way to open the CurrentConfig.tsm file from the Boot folder, byusing Open from Target also referred to as The Red Folder.

Actions Any time a change is made to the System Manager, the Activate Configuration must be done to implement this change into the running system. Note: The first 6 commands in the Actions menu will be sent to the Target system either local or remote.

The tree view on the left provides access to the configurations of the system manager. When an item on the left is selected its information will be displayed on the right. Items can be added to the System Manager be Right-Clicking on an existing item. Become familiar with this, almost every item you wish to add in both the system manager and the PLC will be done by Right- Clicking and select Add... or Append

System Configuration Provides information and settings for the overall TwinCAT System

The settings available from the Properties of the TwinCAT icon can be accessed from here on a remote system.

Real-Time Settings

Settings Here the Base Time is set; no task can be set to a faster interval than the base time.

The CPU limit of 80% means that TwinCAT will consume no more than 80% to run all of its tasks.

Online The Real Time Usage is graphed and the limit from the Settings tab is indicated bythe thick green line

System Latency should be no more than 5 micro seconds.

Note: Image taken from a laptop with power save features and CPU throttling enabled, both of these create latency problems.

Priorities The list of tasks and their priorities can be seen here

Additional Tasks

Task 1 (added by Right-Clicking on Additional Tasks)

These additional tasks are used by C++ code to talk to variables that are linked to hardware I/O

They can also be used for simulation

Route Settings

Current Routes The Remote Computers shown in this list are the same as in the Properties of the TwinCAT icon.

NC Configuration (Numerical Control) This is the software based motion controller of TwinCAT.The software side of all axes are configured here.

Axes The software limits the total number of axes to 255, the real limit is the amount of CPU andRAM in the computer.

PLC Configuration

IEC Project The PLC editor will create a .tpy file that contains addressed variables that can be linked to hardware. The name of the PLC project file is shown directly below the PLC- Configuration

The IEC1131 Tab shows the path of where the .tpy file was located when it was added to the project. If addressed variables are added to the PLC program the ReScan button can be used to update the list of variables in the System Manager

Standard Task The default task in the PLC is the Standard task and runs every 10ms

Inputs of the PLC Program Input variables have a yellow icon, Output variables have a red icon

Once a variable has been linked (connected) to hardware the icon changes as below

PLC Control The PLC Control provides the user with a combination of tools.

The IEC 61131-3 Language editors

A Visualization Editor

Task Configuration Utility

The Beckhoff Compilers specific to the Target Hardware (BC, BX, CX-ARM, X86)

The Left column provides four tabs at the bottom:

POUs Program Organizational Units This will contain the code written by the programmer, Programs, Function Blocks, and Functions

Data Types Here the programmer can create Structures and Enumerations to be used in the PLC code

Visualizations Interface screens for use by Maintenance personnel or Operators can be created.

Resources The resources tab contains several items. The Global Variable Lists, Library Manager, PLC Configuration, and Task Configuration are all accessible from this tab.

Additionally there is a Message Window at the bottom:

Data types and conversions are shown below:

Variable

A Variable is a name given to a location in memory that stores a value

A Variable has up to 5 properties

1. Name

2. Size (Defined by the Type)

3. Value

4. Memory Location

5. PLC Address

In accordance with IEC 61131-3 a variable name must adhere to the following rules

1. Must begin with a Letter or an Underscore

2. Can followed by Letters, Underscores, or Numbers

No distinction is made between Uppercase and Lowercase Letters

Special characters cannot be used (!@#$%^&*)

Blanks or Spaces are not allowed

Repeated or Sequential Underscores are not allowed

Declaration

All variables must be defined between VAR and END_VAR

Place the name of the variable to the left of the colon

Place the data type to the right of the colon

VariableName : VariableType ;

bStart : BOOL ; (*bStart is of type BOOL*)

iProductNumber : INT; (*iProduct Number is of type INT*)

lrPressure : LREAL ; (*lrPressure is of type LREAL*)

Variable Scope

Global Variables can be read and written to from anywhere in the PLC program.

Local Variables can only be written to from within the POU where they are defined

The local variable of any POU can be read by first accessing the POU instance that the variable is defined in and then using the . to access the local variables defined within that POU

Local variables cannot be written to from another POU.

There are 5 languages to write PLC code:

IL Instruction List

LD Ladder Diagram

FBD Function Block Diagram

SFC Sequential Function Chart

ST Structured Text

CFC Continuous Function Chart (Non-IEC)

IL Instruction List

IL has a similar structure to assembly language and is comparable to the statement list language provided by Siemens.

In IL only 1 command can be processed per line of code.

The command is then followed by a variable or a literal value.

For example the following will increase the variable Speed by a value of 5.

LD Ladder Diagram

LD was created with the intention of representing the electrical wiring diagrams of relay logic

LD is a graphical language that displays a power rail on each side that represents the supply and the common of the wiring diagram

The below examples shows a common latching circuit in LD

FBD Function Block Diagram

FBD is a graphical language that is similar to an electronic circuit diagram

The below example has the same functionality as the above latching circuit

SFC Sequential Function Chart

SFC; although defined as a language, is better thought of as a way to organize code and control the sequence of operation

Each Step and Transition in SFC has code inside of it that can be written in any of the other languages including SFC

ST Structured Text

ST is a high level language which looks similar in syntax to PASCAL

ST is the most powerful and flexible of all the languages

When using ST it is important to remember that the variable being written to (the output) is on the left

The below example provides the same latching circuit operation as the ones above

CFC Continuous Function Chart (Non-IEC)

CFC is an additional language provided within TwinCAT, yet it is not a part of the IEC 61131-3 Standard

CFC is a graphical language very similar to FBD

The order of execution is determined by the number, and is able to be modified by the programmer

Declaration

The Declaration of a Function contains 4 parts

The Name of the Function

The Return type of the Function

The Variables to be passed into the Function

The local variables used by the Function

The Name of the Function

Following the Beckhoff coding convention, the name of the Function starts with F_

The same IEC rules for naming of variables apply to the naming of Functions

Following the Name of the Function is the Return Type

A Function can only Return one variable

For example,

The variables to be passed into the function block are enable, time on, and time off values. The variables to be passed out of the function block Below the output variable has been added The variables that are internal to the function block Below the two timers to be used have been instantiated fbTON is of type TON fbTOF is of type TOF

Activity 1 - Blinker

First start TwinCAT PLC Control and choose File > New, a dialog box appears to choose target system type.

Choose target system type

Step 1: Make a function block for blinker. A dialog box appears to create a new POU project by selecting the Function Block and FBD for both type of POU and language of the POU respectively.

New POUStep 2: Next, right click on the function block diagram editor and select box, the function block AND would be placed automatically.

Function block diagram

Step 3: Right click on the function block diagram editor again and select box. Click on the text AND with the cursor and press F2 to obtain the input assistant.

Function block diagram

Step 4: From the input assistant, select Standard Function Blocks > Timer > TON(FB), and click OK. Repeat this step again to place the second function block of timer on-delay.

Input assistant

Function block diagram editor

Step 5: Declare the variable for both the timer on-delay. Right click in between the VAR and END_VAR on the declaration editor and select Auto Declare.

Auto declare

Step 6: Declare both the timer on-delay as timer1 and timer2 respectively, as shown as the diagram below.

Declare variable for timer on-delay

Step 7: Declare the input and output for the function block. On the declaration editor, right click in between the VAR_INPUT and END_VAR for the declaration of input, while VAR_INPUT and END_VAR for the declaration of output. Classify the input as VAR_INPUT and output as VAR_OUTPUT. Set the data type to be Boolean since true/false is only used in this function.

Declare variable for input

Declare variable for output

Declaration editor

Step 8: On the function block diagram, click on the text ??? with cursor and press F2 to obtain the input assistant. In the local variable, select and click OK to link the variable input and output and variables on the function block diagram. Next, set the PT to 1 millisecond with the format t#1ms as the time would begin counted in millisecond.

Input assistant for variable input, variable output and variables

Step 9: Set the second input of the AND block diagram as timer2 output, as shown in the diagram below. Then, right click on it and select negate to negate the input.

Input assistant for the second input

Complete function block diagram for blinker

Step 10: Create a program for ladder diagram.

New POU

Step 11: On the ladder diagram editor, right click and select Box with EN, this command is used to insert function block into a LD network. Next, click on the text ??? with cursor and press F2 to obtain the input assistant. From the input assistant, select User Defined Function Block > blinker (FB).

Input assistant with user defined function blocks

Step 12: Declare the input and output to be Boolean. First, right click in between the VAR and END_VAR and select Auto Declare. Next, obtain the input assistant and link both input and output to the function block on the ladder diagram editor, as shown in the picture below.

Step 13: Add a new object in visualizations. On the visualizations editor, draw a button for input and a circle for output, as shown in the diagram below.

Complete visualizations for blinker

Step 14: Double click on the button to obtain the regular element configuration dialog box. Select text and enter the text in the content field for the button. Next, select input and tick toggle variable and press F2 on the blank column to obtain the input assistant. From the input assistant, select the blinker input in MAIN PRG.

Step 15: Double click on the circle, select color and click inside and select green color for the alarm color. If the variable is true, the element will be displayed in its alarm color. Next, select variables change color and press F2 on the blank column to obtain the input assistant. From the input assistant, select the blinker output in MAIN PRG. Click OK.

Step 2: Save and name the POU project. Go to TwinCAT System Manager, right click on the PLC - Configuration and select Append PLC Project to open the TPY file for the PLC configuration. Next, click activate configuration to implement the PLC into the running system.

TwinCAT System Manager

Open the TPY file

Step 16: Go back to TwinCAT PLC Control. Build the project by clicking project and then build.

Step 17: Login the project by clicking online and then login. Next, click run to run the simulation.

Step 18: On the declaration editor, double click the word FALSE at the blinker input and press "F7. When it becomes TRUE, the blinker output will start blinking.

While running the simulation

Before click the button on the visualizations

After click the button, it starts to blink.

Activity 2 - Conversion

Step 1: This activity is to convert INTEGER to LREAL with the division of 10. In order to add a new POU, right click on the POU folder and select add object. In this case, structure text (ST) is used.

New POU

Step 2: On the structure text editor, type conversion := (INT_TO_LREAL (input)/10); , as shown in the picture below.

Step 3: Declare the variable input. Set the data type to be integer.

Declare variable input

Step 4: Create a program for ladder diagram.

New POU

Step 5: On the ladder diagram editor, right click and select Box with EN, this command is also used to insert a function into a LD network. Next, click on the text ??? with cursor and press F2. From the input assistant, select User Defined Function Block > conversion (FUN).

Input assistant for conversion (FUN)

Step 6: Declare the input and output to be Boolean. First, right click in between the VAR and END_VAR and select Auto Declare. Next, obtain the input assistant and link both input and output to the function on the ladder diagram editor, as shown in the picture below.

Declare variable for input

Declare variable for output

Complete ladder diagram for conversion

Step 7: On the visualizations editor, draw rectangles for integer and long real in order to display the values. In the visualization element configuration dialog box, select any primary colors in the color category for the inside area or for the frame of the element.

Step 8: Specify a text for each element in the text category by entering the text in the content field.

Complete visualizations for conversion

Step 9: Include %i and %s into the text field for integer and long real respectively.

Regular Element Configuration dialog box (text content)

Step 10: The value of the variable which is defined in Textdisplay in the variables category, it will be displayed in online mode in the visualization object. %s and %i will be replaced by the value. Press F2 on the Textdisplay to obtain the input assistant. From the input assistant, select the conversion input and output for integer and long real respectively.

Regular Element Configuration (text display)

Step 11: Build the project by clicking project and then build.

Step 12: Login the project by clicking online and then login. Next, click run to run the simulation.

Step 13: Double click on the word input_conv and set any value for it.

Write variable for conversion input

Step 14: Press F7 to convert the value after set up a value for conversion input.

While running the simulation

Visualizations

Activity 3: File Access

The log stores in an order actions that occur during an online session.

Step 1: Create a new POU, then, right click on the POU folder and select add object. In this case, structure text (ST) is used.

Step 2: Structure text code.

TON1(IN:=NOT TON1.Q , PT:=t#1s);

NT_GetTime1(NETID:='' ,START:=TON1.Q ,TMOUT:=t#2s ,TIMESTR=> );

(

(*IF Error1 THENbLog:=TRUE;Error1:=FALSE;Data_string := CONCAT(SYSTEMTIME_TO_STRING(NT_GetTime1.TIMESTR),' -->This is error 1 $N');END_IF

IF Error2 THENbLog:=TRUE;Error2:=FALSE;Data_string := CONCAT(SYSTEMTIME_TO_STRING(NT_GetTime1.TIMESTR),' -->This is error 2 $N');END_IF*)Data_string := CONCAT(CONCAT(CONCAT(CONCAT(CONCAT(SYSTEMTIME_TO_STRING(NT_GetTime1.TIMESTR),' Data1 :'), INT_TO_STRING(Data1)),' Data2 : '),INT_TO_STRING(Data2)),'$N');Log_File1(FILE_PATH:=Path , LOG_DATA:=bLog , DATA_STRING:=Data_string );

(*IF NOT Log_File1.bBusy THENbLog:=FALSE;END_IF*)

Step 3: Declare the variables on the declaration editor.

Step 4: Create a folder and name it Logs in disk C. Next, create another folder and name it LOG1 in the Logs folder

Step 5: Enter the directory for the project log. The maximum number of online sessions to be stored can be entered in the menu item Project > Options > Log dialog. If this number is exceeded, the oldest record is deleted to make room for the newest one. Next, tick all the four particulars in the category: user actions, internal action, status change, and exception.

Step 6: Build the project by clicking project and then build.

Step 7: Login the project by clicking online and then login. Next, click run to run the simulation.

Step 8: Enter the data value by double clicking the word data1, data2, data3.

Step 9: Select the menu item Window and then click log to open the log, which the log activity can be checked here.

Step 10: The log file is also stored in an external file entitled LOG1.text that has been created in disk C, as shown in the picture below. Noted: the project log in an external file only occurs during an offline session.

Activity 4: Send, receive, analyze, and store a string in an array and log file (with date and time) via TCP/IP

Twincat TCP/IP enables the implementation of one or several TCP/IP servers and/or clients within the TwinCAT PLC. It allows the establishment/disconnection of communication as well as for the exchange of data (send and receive).

Step 1: Configuration of TCP/IP properties

For Windows XP, click start > Control Panel > select and double click Network and internet connections > select and double click Network Connections. Next, double-click the Local Area Connection icon, highlight Internet Protocol (TCP/IP) tab in the Local Area Connection Properties window that appears:

Then, click Properties, the TCP/IP Properties window will appear. Select Use the following IP address, if the routers LAN IP address is 192.168.1.1, type in IP address 192.168.0.x ( x is from 2 to 253). In this case, 192.168.0.15 is used for the IP address and subnet mask is 255.255.255.0. Click OK to save.

Step 2: Test the TCP/IP connection by using the ping command

Go to Start > Run and enter cmd to open the command window. Next, type ping 192.168.0.15 on the command window and press Enter. The picture below illustrates the result.

Step 3: In TwinCAT PLC Control, several function blocks are used in the main program: fbClientServerConnection, fbSocketSend, fbSocketReceive, and timer-on delay. In the library manager, Tcplp.lib and TcSocketHelper.lib are included.

The function block FB_ClientServerConnection can be used to establish or remove a client connection. A typical client application establishes the connection with the server via FB_ClientServerConnection function block. In the next step instance of the FB_SocketSend and FB_SocketReceive are used to exchange data with the server.

PROGRAM MAINVAR(*Fbs*)fbServerClientConnection: FB_ServerClientConnection;fbSocketSend: FB_SocketSend;fbSocketReceive: FB_SocketReceive;fbTON_RecvTimer: TON;(*Vars*)nServerPort: UDINT:=200;hServer : T_HSERVER;hSocket: T_HSOCKET;bEN_SERV_LISTEN: BOOL;bEN_SERV_CONN: BOOL;bEXE_SERV_RECV: BOOL;tRecv: TIME:=t#10ms;

(*Operation*)sDATA_Current: STRING(255);bSTATE_Machine: BOOL;bSTATE_Alarm: BOOL;iVALUE_SetValue: REAL;iVALUE_CurrValue: REAL;logFile: Log_File;

Path : STRING := 'C:\Logs\LOG1.txt'; (*CE:'Hard Disk:\LOG1.txt' |XP: 'C:\LOG1.tx*)Data_string : STRING(255);Log_data : BOOL;

reset_log : BOOL;set: SR;

string1: STRING;string2: STRING;string3: STRING;stringlength: INT;

mt: BOOL;midstring: STRING;pos1: INT;pos2: INT;datestring: STRING;datastring: STRING;

TON1: TON;NT_GetTime1: NT_GetTime;string_check_length: INT;X : INT;Y: INT;NREC_BYTE: UDINT; IP_Adress: STRING(255) :='192.168.0.15'; fbClientServerConnection: FB_ClientServerConnection;END_VAR

The code above shows the declaration part for the main program.

Declaration part for receiving a string

PROGRAM Receive_StringVARTON1: TON;NT_GetTime1: NT_GetTime;string1: STRING;string2: STRING;string3: STRING;stringlength: INT;mt: BOOL;midstring: STRING;pos1: INT;pos2: INT;datestring: STRING;datastring: STRING;logFile: Log_File; Path : STRING := 'C:\Logs\LOG1.txt'; (*CE:'Hard Disk:\LOG1.txt' |XP: 'C:\LOG1.tx*)Data_string : STRING(255);

Log_data : BOOL;string_check_length: INT;X : INT;Y: INT;Log_txt_array1: Log_txt_array;

END_VAR

Structure text code for receiving a string

string_check_length:=LEN(sDATA_RECV);TON1(IN:=NOT TON1.Q , PT:=t#1ms);NT_GetTime1(NETID:='' ,START:=TON1.Q ,TMOUT:=t#2s ,TIMESTR=> );

logFile(FILE_PATH:=Path , LOG_DATA:=Log_data , DATA_STRING:=Data_string , bBusy=> BUSY_LOG);

IF string_check_length > 0 THEN

Data_string := CONCAT(CONCAT(CONCAT(CONCAT(SYSTEMTIME_TO_STRING(NT_GetTime1.TIMESTR), ' '),'WMS -----> PLC '), sDATA_RECV),'$N');

Log_data := 1;X := X + 1;IF X > 1 THEN(* log data to arrray*)LOG_TXT_ARRAY [0] := sDATA_RECV;Log_txt_array1(Array_Name:= LOG_TXT_ARRAY);

sDATA_RECV :='';BUSY_LOG := 0;Log_data := 0;X :=0;END_IFEND_IF

Using the function block FB_SocketReceive, data from the remote client can be received via the TCP/IP connection server. The connection will have to be established via the function block FB_ClientServerConnection. The data can be received or sent within a TCP/IP network. During the process, a rising edge is generated at the bExecute input for every 1 millisecond. The nRecBytes output returns the number of the last successfully received data bytes.

Declaration part for sending a string

PROGRAM Analyse_stringVARx: INT;mid_string: STRING(255);Pos1: INT;Pos2: INT;Data_001: STRING (255);Data_002: STRING (255);Data_003: STRING (255);Data_004: STRING (255);Data_005: STRING (255);Data_006: STRING (255);Data_007: STRING (255);Data_008: STRING (255);Data_009: STRING(255);Data_010: STRING (255);Data_011: STRING (255);Data_012: STRING (255);Data_013: STRING (255);Data_014: STRING (255);Data_015: STRING (255);Data_016: STRING (255);Data_017: STRING (255);Data_018: STRING (255);Data_019: STRING (255);Data_020: STRING (255);

TON1: TON;NT_GetTime1: NT_GetTime;Send_string : STRING (255);

String_len: INT;Send_timing: INT;

Path : STRING := 'C:\Logs\LOG1.txt'; (*CE:'Hard Disk:\LOG1.txt' |XP: 'C:\LOG1.tx*)Data_string : STRING(255);Log_data2 : BOOL;logFile: Log_File;log_write: BOOL;

END_VAR

Structure code for sending the string

IF x = 0 THENx := 100;END_IF

String_len := LEN(Log_txt_array[x] );TON1(IN:=NOT TON1.Q , PT:=t#1s);NT_GetTime1(NETID:='' ,START:=TON1.Q ,TMOUT:=t#2s ,TIMESTR=> );

IF String_len = 0 THENx := x -1;ELSEmid_string := Log_txt_array[x];pos1 :=0;pos1 := FIND(mid_string,'');IF pos20 THENmid_string:= LEFT(mid_string,pos2-1);Data_001:=LEFT(mid_string,6);Data_002:=MID(mid_string, (LEN(mid_string)-6),7);

Send_string:= CONCAT(CONCAT(CONCAT(CONCAT(SYSTEMTIME_TO_STRING(NT_GetTime1.TIMESTR), ' '),'WMS