BECKHOFF TwinCAT 3 Basics

TR3020 | Training for new users | Overview

TwinCAT 3 New Automation Technology

Training für Umsteiger

Identifier Indentifier serves to assign individual names to variables, data types, functions, etc. The identifier starts with a letter or underscore followed by numbers, letters and underscore No distinction is made between upper and lower case The following are not permitted special characters (!, “, §, $, etc.) spaces consecutive underscores umlauts

TwinCAT Training: Programmer

29.10.2013

2

Keywords Keywords are identifiers specified by IEC61131-3. They are thus fixed components of the syntax and therefore may not be used for other purposes.

Examples Standard operators AND, OR, NOT… Standard types BOOL, INT, REAL... Types TYPE, STRUCT Block types FUNCTION, FUNCTION_BLOCK, PROGRAM


29.10.2013

3

Keywords and comments The comments are delimited by character strings with (* or *) at the beginning and at the end. Comments may be placed wherever spaces are also permitted. Exception: within string literals.

(*digitale Eingänge*) bStart AT %IX0.0 :BOOL;(*Anlagenstart*) (*analoge Eingänge*) TemK1 AT %IW10 (*Byte 10-11*) :WORD;

Comments to the end of the line bStart AT %IX0.0 :BOOL; // Anlagenstart


29.10.2013

4

Elementary data types Type

Lower

Upper

BOOL

FALSE

TRUE

Size

Prefix x b

BYTE

8 BIT

by

Bitstring

WORD

16 BIT

w

Bitstring

DWORD

32 BIT

dw

Bitstring


29.10.2013

5

Elementary data types Typ

Lower

Upper

Größe

Präfix

SINT

-127

127

8 Bit

si

USINT

0

255

8 BIT

usi

INT

-32768

32767

16 BIT

i

UINT

0

65535

16 BIT

ui

DINT

-134 217 728

134 217 727

32 BIT

di

UDINT

0

4294 967 295

32 BIT

udi

64 BIT

li

64 BIT

uli

LINT ULINT

0

Detail slides •Overflows •Example: EL3102 •Example: KL2531 TwinCAT Training: Programmer

29.10.2013

6

Data types 1: Elementary data types Type

Lower

Upper

Size

Prefix

TIME_OF_DAY

TOD#0:0:0

TOD#23:59: 59

32 Bit

tod

DATE

D#1970:01:01

D#2106 ???

32 Bit

date

DATE_AND_TIME

DT#1970:01:01:00:00:00

DT#2106 ???

32 Bit

dt

TIME

T#0s

T#49d17h2m 32BIT 47s295ms

tim

Detail slides DT example - reading the system time DT example - working with standard operators


29.10.2013

7

Elementary data types Type

Lower

Upper

Size

Prefix

REAL

4 Byte

r

LREAL

8 Byte

lr


29.10.2013

8

Data types: STRING Type

Description

Example

Size

Prefix

STRING

String in ASCII code. Standard length 80 characters. Maximum length 255. Strings are zero-terminated

‘1234ABCDE‘

80 +1

s

‘ABCDE$R$L‘ ‘ABCDE$0D$0A‘

String length specifications Example declaration

Assignment

Result SIZEOF

Result LEN

sVar : STRING;

sVar:=‘ABC‘;

81

3

sVar1 :STRING(1);

sVar := ‘X‘;

2

1

sVar: STRING(255);

sVar:=‘ABC‘;

256

3


29.10.2013

9

Data types: STRING Constants $<2 Hex values>

ASCII Code

$0D

CR

$R

$r

CR

$L

$l

Line Feed

$N

$n

New Line

$T

$t

Tab

Detail slides Example: FIND Example: string functions LEN, REPLACE String conversion with Union


29.10.2013

10

Data types: WSTRING Type

Description

Example

Description

Pre fix

WSTRING

String in Unicode format

“Обучение“

Level 0,Block 0x0400-0x4FFF Cyrillic

ws

“培训、讲座、研讨会“ “Training, seminar”

Level 0 Block 0x00000x007F Basic Latin


29.10.2013

11

Data types: Examples of literals Variable Type

Examples

BOOL

TRUE

2#1

16#1

1

FALSE

2#0

16#0

0

WORD, DWORD

2#1010111111111110

16#AFFE

45054

INT

2#1000000000000001

16#8001

-32768

TIME

t#1h

t#60m

t#3600000ms

t#0.5d

t#12h

t#43200000ms

d

day

h

hours

m

min

s

sec

ms

ms

REAL

t#30m18s90ms

t#0.505025h

0.3333

3.333e-1

t#1818090ms


29.10.2013

12

Data types 1: Variable declaration el. data types A variable possesses a name behind which a value (number, string, date, etc.) is concealed. The variable name is a type of description of the path to the declared data. Variables are characterised above all by the fact that their contents can be changed at runtime.

Identifier

Data type

Initial value

bStellerUntenLinks:BOOL:=TRUE;

The physical-logical storage location of this variable is unknown to the user (unlocated)

The degrees of freedom and restrictions in the assignment of the identifiers can be found on the slide entitled Identifiers and Prefixes TwinCAT Training: Programmer

29.10.2013

13

Data types 1: Located variables It is possible when declaring a variable to link the name with an address that must be explicitly specified. For the allocation of inputs and outputs of the hardware the incomplete location is to be carried out with I* and Q* Identifier

AT

%I

Data type;

%Q*


29.10.2013

14

Data types 1: Located variables Completely located variables. Identifier

AT

%I

X

%Q

B

%M

W

Byte

.

Bit

Type

Byte

D

These variables possess a clear address (located) In TwinCAT 3 incompletely located variables can be used for inputs and outputs Applications for %M variables can be solved simply with Unions and direct masking

Detail slides Detail - Replace %MB by UNION TwinCAT Training: Programmer

29.10.2013

15

Data types 1: Address division Examples: IX10.7

IX10.6

IX10.5

IX10.4

IX10.3

IX10.2

IX10.1

IX10.0

Din0 AT%IX10.0 : BOOL;

IB10

IB1

IB0

Ain AT%IB0 : INT; equivalent

IW0

Ain AT%IW0 : INT; IX22.7

IX22.6

IX22.5

IB23

IX22.4

IX22.3

IB22

IX22.2

IX22.1

IB21

IW22

IB20 IW20

ID20

IX22.0

BitVar AT%IX22.1 : BOOL; Posi AT%IB20 : UDINT; equivalent

Posi AT%ID20 : UDINT;


29.10.2013

16

Data types 1: Variable classes, scope Local variables are restricted to the block in which they were declared. Keywords VAR .. END_VAR VAR_INPUT .. END_VAR VAR_IN_OUT ..

Global variables are known in each block within a project. Keywords VAR_GLOBAL .. END_VAR VAR_CONFIG .. END_VAR

END_VAR VAR_OUTPUT .. END_VAR


29.10.2013

17

Data types 1: I/O directly in an FB instance In an FB the inputs and outputs to the periphery are to be created directly as local variables

Implementation TwinCAT Training: Programmer

29.10.2013

18

Data types 1: Access via the located variables The variable ‘locVar’ locally declared in Program B can be directly accessed from Program A via address %MB2.

Project machine PROGRAM A

PROGRAM B

VAR

VAR locVar AT%MB2:WORD; END_VAR

END_VAR

LD %MB2


29.10.2013

19

Data types 1: Overlaps in the scope Project machine VAR_GLOBAL Var1:WORD; END_VAR

PROGRAM A VAR Var1 :WORD; END_VAR

Example name: Gvl1

As shown on the left, there is an overlap in the scope. In this case the locally declared variable Var1 is loaded into the accumulator. The global variable can also be accessed with Namespaces.

LD Var1 LD Gvl1.Var1


29.10.2013

20

Data types 1: PERSISTENT attribute Special properties of variables can be defined using attributes. Example: The variable(s) are saved when the PLC is shut down and loaded back on restarting.


29.10.2013

21

Data types 1: Initialisation and CONSTANT Initial values, the variables are to be preset with a certain value when starting/resetting the PLC. VAR AccelerationTime : TIME := T#3s200ms; END_VAR Read-only: VAR_GLOBAL CONSTANT pi:REAL:=3.141592654;

Global

END_VAR VAR CONSTANT pi:REAL:=3.141592654;

Also locally possible

END_VAR TwinCAT Training: Programmer

29.10.2013

22

Data Types 2: Derived data types The user can create his own data types on the basis of the elementary data types or data types that have already been created. The newlycreated data types are visible in the entire project. The declaration starts with TYPE and ends with END_TYPE.

Parent type

Name

Data type

New value

Derivation

Name

Data type

Initial value

Area

Inherit ance

Initial value

Area


29.10.2013

23

Data Types 2: References (alias types) The purpose of the selfdefined data type Reference is to generate an alternative name for a variable, constant or function block. Create your references as objects in the object organiser on the Data Types tab. They start with the keyword TYPE and end with END_TYPE.

Syntax: TYPE :; END_TYPE Type

Declaration


29.10.2013

24

Data Types 2: References (alias types) Example: A global string variable is transferred to various blocks. If changes are made to the Global Variables, the declarations must also be changed in every block


29.10.2013

25

Data Types 2: References (alias types) If a type has been created for the string, further changes are made only to the type


29.10.2013

26



29.10.2013

27



29.10.2013

28

Data Types 2: Enumerated type (Enum) An enumerated type is a self-defined data type consisting of a number of string constants. These constants are called enumeration values. The enumeration values are always known in the entire project. It is best to create your enumerated types as objects in the object organiser on the Data Types tab. They start with the keyword TYPE and end with END_TYPE. Syntax: TYPE :( ,, ...,); END_TYPE Example: TYPE Woche:(Mo, Di, Mi, Dn, Fr, Sa, So:=10);(*Mo = 0 Di = 1.. .. Sa = 6 So = 10*) END_TYPE TYPE Richtung:(Up, Dn);(*Up = 0 Dn = 1*) END_TYPE

The same enumeration value can be used twice via Namespace. Example: Woche.Dn Richtung.Dn TwinCAT Training: Programmer

29.10.2013

29

Data Types 2: Enumerated type (Enum) Example: signal light without Enum: Declaration

Use

Online


29.10.2013

30

Data Types 2: Enumerated type (Enum) Example: signal light with Enum: Type

Use

Declaration

Online


29.10.2013

31

Data Types 2: Structure declaration Example: KL5101 Encoder Terminal Structures are self-defined data types. They are an important aid to better administration of the process data. In addition, the structures are suitable for encapsulated data transfer to function blocks. Structures can be used like individual element variables.


29.10.2013

32

Data Types 2: Structures instancing

ST_KL5101In_1 AT%I* : KL5101_IN ST_KL5101Out_1 AT%Q* : KL5101_OUT


29.10.2013

33

Data Types 2: Arrays Arrays represent lists or data fields. All elements in the arrays are of the same type. Naturally arrays can also consist of own data types (structures). One, two and three-dimensional arrays are possible. VAR Feld_1 :ARRAY[0..9] OF BYTE; Feld_2 :ARRAY[0..9, 0..1] OF UINT; Feld_3 :ARRAY[0..9, 0..1,0..1] OF DINT; END_VAR

1-dimensional 2-dimensional 3-dimensional

There is a possibility to place a data field in a directly addressed memory location VAR Feld_1 AT%MB100:ARRAY[1..10] OF BYTE; END_VAR Access to the sub-elements of a data field Feld_1[2] := 120; (* Expliziter Zugriff*) Feld_2[i,j] := EXPT(i,j); (*Indizierter Zugriff*)


29.10.2013

34

Data Types 2: Limit transgressions A dangerous state can arise if an area outside the data field is accessed in the PLC program. VAR Feld_1 :ARRAY[1..10] OF BYTE; Feld_2 :ARRAY[1..10, 2..5] OF UINT; END_VAR

i:= 9 Feld_1[i+2] := 120;

9

Feld_1[9];

0

Feld_2[1,2];

120


29.10.2013

35

Data Types 2: CheckBounds (FUN) The access can be monitored by the PLC at PLC runtime This function enables a limit transgression occurring in the program to be recognised and rectified.

FUNCTION CheckBounds :DINT VAR_INPUT I,L,U : DINT; END_VAR

IF I< L THEN Error case

CheckBounds := L;

ELSIF I > U THEN Error case i Min Max

Limited value

CheckBounds := U;

ELSE “OK” case

CheckBounds := I;

END_IF


29.10.2013

36

Data Types 2: Adding CheckBounds 1 (FUN) Adding Checkbounds:


29.10.2013

37

Data Types 2: Adding CheckBounds 2 (FUN)


29.10.2013

38

Data Types 2: Method of operation of CheckBounds (FUN) Example: user error source code

Checkbounds is “compiled-in” in XAR

10

Do not write, it is called automaticall y (not visible in the code)

10 Can be checked with call build: TwinCAT Training: Programmer

29.10.2013

39

Note about further checker functions The following further checker functions are possible from TwinCAT 2.8: Check for division by 0 CheckDivByte CheckDivWord CheckDivDWord CheckDivReal Check value ranges CheckRangeSigned CheckRangeUnsigned (see appendix)


29.10.2013

40

Data Types 2: Combination: structures and arrays An array can consist of structures: Structure: TYPE DrillPos : STRUCT XPos: FeedrateX: AccelerationX: DeccelerationX: JerkX: YPos: FeedrateY: AcceleartionY: DeccelerationY: JerkY: FeedDrill: Kuehlen: END_STRUCT END_TYPE

LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; LREAL; BOOL; (*Pumpe ?*)

Declaration of the array:

Positions :ARRAY[0..100] OF DrillPos; TwinCAT Training: Programmer

29.10.2013

41

Data Types 2: Combination: structures and arrays Access to “Drillpos 55”: Access: MoveXAx (*FB Instanz*) ( Execute:=

TRUE,

Position:=

Positions[55].XPos ,

Velocity:=

Positions[55].FeedrateX

Acceleration:=

Positions[55].AccelerationX,

Deceleration:=

Positions[55].DeccelerationX,

Jerk:=

Positions[55].JerkX,

Direction:=

.........,

Axis:=

.............,

); TwinCAT Training: Programmer

29.10.2013

42

Block types In IEC61131-3 there are three types of block covered by the generic term POU (PROGRAM ORGANISATION UNIT): Program Function Block Function


29.10.2013

43

Block types: program PRG Program PRG Called by a task (one program can call another) Calls: FBs, functions, (programs) Local variable: static, i.e. the local data are available again in the next cycle. Inputs: usually 0, but VAR_INPUT possible Outputs: usually 0, but VAR_OUTPUT possible Transfer by reference VAR_IN_OUT likewise possible Monitoring: Local data are immediately visible in the online mode of the PLC control Use: Main programs, Main, Manual, Automatic, etc.


29.10.2013

44

Block types: function block FB Function block FB Called by programs or other FBs Calls: FBs, functions, Local variable: static, i.e. the local data are available again in the next cycle. Can be instanced in case of multiple calls (multipliable). Each FB call can have its own local data. Inputs: 0,1,2,3…VAR_INPUT Outputs 0,1,2,3.. VAR_OUTPUT Transfer by reference 0,1,2,3.. VAR_IN_OUT Monitoring: In the online mode of the PLC control the instance of the call concerned must first be specified. The local data are then visible for each call. Use: multiple-used modules, each of which requires its own data area. Step chains...


29.10.2013

45

Block types: Function: FC Function: FC Called by programs, function blocks and other functions Calls: Functions Local variable: temporary, i.e. the local data are available only for the processing time of the function. Afterwards this data area is used by other functions. Inputs:

1,2,3........ VAR_INPUT

Outputs: precisely 1!, but structure variable possible. The name of the output is at the same time the name of the function. Transfer by reference

1,2,3........ VAR_IN_OUT ,

Monitoring: In the online mode of the PLC control only “???” are visible for the local variables, since this data area is used by all functions in the cycle and monitoring (debug) takes place only at the cycle limits. Remedy: program development with breakpoints Use: algorithms where the result is available after a run. Scaling, comparison, etc.


29.10.2013

46

ST “Structured Text”: Operators Operation put in parentheses Function call Exponentiation Negate Build. complements Multiply Divide Modulo Add Subtract Compare Equal to Not Equal to BOOL AND BOOL XOR BOOL OR

Symbol Binding strength (expression) Strongest binding Function name (parameter list) EXPT NOT * Same binding strength, processing from “left to right” / (10/2*5 = 25 ) MOD + Same binding strength <,>,<=,>= = <> AND XOR OR

Weakest binding TwinCAT Training: Programmer

29.10.2013

47

ST “Structured Text”: Instructions Instruction

Example

Assignment:=

PosWert := 10;

Calling a Function Block

Ton1(IN:=Start, PT:=T2s); Output:= Ton1.Q;

RETURN

RETURN;

IF

more precise explanations and examples on the following pages

CASE FOR WHILE REPEAT EXIT Empty instruction

;


29.10.2013

48

ST: IF instruction Is needed to branch in a program, depending on conditions. With the IF instructions it’s not possible to jump back in the PLC cycle. “GOTO” is also not available

Keywords:

IF

THEN

ELSIF ELSE END_IF


29.10.2013

49

ST: IF instruction

IF Condition THEN Instruction block; END_IF

No Condition Yes

Instruction block


29.10.2013

50

ST: IF instruction

IF a>b THEN Instruction block A; ELSE Instruction block B; END_IF

Condition

No

Yes

Instruction block A

Instruction block B


29.10.2013

51

ST: IF instruction IF Condition1 THEN Instruction block A; ELSE IF Condition2 THEN Instruction block B; Condition 1 ELSE No Yes IF Condition3 THEN Condition 2 Instruction block C; ELSE Yes Instruction block D; END_IF END_IF END_IF Instruction Instruction block A

block B

No Condition 3 No Yes Instruction block C

Instruction block D


29.10.2013

52

ST: IF instruction

IF Condition1 THEN Instruction block A; ELSIF Condition2 THEN Instruction block B; ELSIF Condition3 THEN Instruction block C; ELSE Instruction block D; END_IF

Condition 1 No Yes Condition 2 No Yes Condition 3 No Yes Instruction block A

Instruction block B

Instruction block C

Instruction block D


29.10.2013

53

ST: IF instruction What can the “BOOLEAN EXPRESSION” be? Conditions: BOOLEAN variable Comparison Function calls

Querying of FB instances NO FB call!

IF bVar THEN . IF a>b THEN . IF LEFT(STR:= strVar, SIZE:=7) = 'TwinCAT' THEN . IF Ton1.Q THEN . IF Ton1(IN:=bVar, PT:=T#1s ) THEN


29.10.2013

54

ST CASE Instruction CASE Selection criterion OF 1:

Selection criterion = 2 or 4 or 6

Instruction 1

2, 4, 6: Instruction 2

Selection criterion = 1

7..10: Instruction 3

Selection criterion = 7 or 8 or 9 or 10?

No

Yes

..

No

ELSE

Yes

Default instructions

No Yes

END_CASE; Two identical values may not be available for selection in the list.

Instruction 1

Instruction 2

Instruction 3

Default instructions


29.10.2013

55

ST: CASE instruction: possibility for a step chain / state machine Instructions for the step (Actions)

CASE State OF 0:

Q0:=TRUE; IF Transition THEN state := 1; END_IF

1:


2:

“Step-further condition” (Transition)


3:


END_CASE


29.10.2013

56

ST: CASE instruction “Integer Selector Value” with constants CASE State OF 0:

Instructions;(*State=0*)

Instructions if state = 0

IF ……THEN 1:



2:



3:



END_CASE


29.10.2013

57

ST: CASE instruction “Integer Selector Value” with Enum types

Enum-Typ: TYPE Schritte : (INIT:=0, START, AUTOMATIK, ENDE); END_TYPE

CASE State OF INIT:


START:


AUTOMATIK:


ENDE:


END_CASE


29.10.2013

58

ST: CASE instruction: suggestion for a step chain / state machine TYPE Schritte : ( INIT:=0, START, AUTOMATIK, ENDE); END_TYPE

Instructions for the step (Actions)

CASE State OF INIT:

Q0:=TRUE; IF Transition THEN state := START; END_IF

START:

“Step-further condition” (Transition)

Q1:=TRUE; IF Transition THEN state := AUTOMATIK; END_IF

AUTOMATIK: Q2:=TRUE; Step IF Transition THEN state := ENDE; END_IF ENDE:

Q3:=TRUE; IF Transition THEN state := INIT; END_IF

END_CASE TwinCAT Training: Programmer

29.10.2013

59

ST: CASE instruction “Integer Selector Value” with constants CASE State OF

VAR CONSTANT Step1 : INT:=

0;

Step1:


Step2 : INT:=

1;

Step2:


Step3 : INT:=

2;

Step3..Step4:

Instructions;(*State=2 oder 3*)

Step4 : INT:=

3;

END_CASE

END_VAR

VAR State:INT; END_VAR


29.10.2013

60

ST: Repeat instructions The process sequence often requires the multiple processing of precisely the same program sequences, where their number is known only at runtime. Disadvantage of loops: In the case of wrong programming, an infinite number of repetitions takes place. If a continuous loop is executed, this does not impair the start of the time slices (real-time). Tasks with a higher priority will still be executed on time. Tasks with a lower priority will no longer be executed. Forced switchover to Win NT

1 e.g.: 1ms

1

2 2ms

1‘

3 3ms

1‘‘

Begin of a new time slice

4 4ms

1‘‘‘

1‘ 5ms


29.10.2013

61

ST: Loops (overview) All loops can be terminated with the help of the EXIT instruction, regardless of the abort condition.

Expression

Processing

n cycle fix

FOR

SINT/INT/DINT

Yes Instructions follow condition

WHILE

BOOL

Instructions No follow condition

REPEAT

BOOL

Condition follows instructions

No


29.10.2013

62

ST: FOR loop At the beginning of the loop the Cycle n control variable i is set to the starting value (see example). The control variable is decremented or incremented in each loop, depending on the step size (value after the keyword BY). If i exceeds the end value (after TO), the loop is no longer processed.

Start i:=StartValue

Yes

i >EndValue No Instruction block

i: = i + step size

FOR i:=1 TO 12 BY 2 DO Feld[i]:=i*2;(*Anweisung*) END_FOR Cycle n TwinCAT Training: Programmer

29.10.2013

63

ST: WHILE loop The instruction block of a WHILE loop is executed continuously until the Boolean expression returns TRUE. The abort condition can contain variables that can be changed in the instruction block. If the Boolean expression is FALSE at the beginning, then the instruction block of the WHILE loop is not processed. i:=0; WHILE i<100 DO Feld[i]:=i*2;(*Anweisung*) i:=i+1; END_WHILE

Cycle n

Yes

Boolean expression

No

Instruction block i: = i + step size

Cycle n TwinCAT Training: Programmer

29.10.2013

64

ST: REPEAT loop Cycle n

The instruction block of a REPEAT loop is executed as long as the Boolean expression is satisfied. The instruction block is processed at least once.

Instruction block i:= i + step size

i:=0; REPEAT Feld[i]:=i*2;(*Anweisung*) i:=i+1; UNTIL i>100

No

Boolean expression Yes

END_REPEAT Cycle n TwinCAT Training: Programmer

29.10.2013

65

ST: FB calls in ST VAR TON1:TON; END_VAR TON1 (IN:= NOT TON1.Q , PT:=T#1s ); Q0:= TON1.Q;

TON1(IN:= NOT TON1.Q, PT:=T#1s , Q=>Q0 );


29.10.2013

66

ST: FB calls in ST (alternative) VAR TON1:TON; END_VAR

TON1.IN:= NOT TON1.Q; TON1. PT:=T#1s; TON1(); Q0:= TON1.Q;


29.10.2013

67

ST: FC calls in ST Result:=Scale (x:=Eingang, xug:=0.0, xog:=32767.0, yug:=0.0,yog:=100.0); (* Gleichwertig:*) Result:=Scale (Eingang, 0.0, 32767.0, 0.0, 100.0); (* Gleichwertig:*) Result:=Scale (

xog:=

x:=

Eingang,

xug:=

0.0,

32767.0, yug:=

0.0,

yog:=

100.0

); In case of functions, all inputs must be occupied TwinCAT Training: Programmer

29.10.2013

68

ST: FC calls in ST Result := Scale (x:=Eingang, xug:=0.0, xog:=32767.0, yug:=0.0,yog:=100.0);

Result

CALL

Input parameters

(* Gleichwertig:*) Result:=Scale

( x:= xug:= xog:= yug:= yog:= );

Eingang, 0.0, 32767.0, 0.0, 100.0


29.10.2013

69

BECKHOFF TwinCAT 3 Basics

Recommend Documents