TwinCAT IEC61131-3
May 5, 2017 | Author: Nigo Villan | Category: N/A
Short Description
TwinCAT IEC61131-3...
Description
TwinCAT IEC61131-3
1
26.07.2007
Overview
Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
2
26.07.2007
The IEC 61131-3 IEC 61131-3
-1 General definitions and typical function (cyclic processing, process image input and output)
-2 Environmental conditions and conditioning classes of the control and the programming devices. (temperature, air humidity)
-4 Guide line for the system analysis of the user, the system selection, the realisation of the application, as well as maintenance and servicing
-5 Definition of the communication via funcion blocks and communication via access paths
3
(additionally to –3)
-3 Rules for using and implementation of PLC programming languages
-6 Communication via fieldbus.
-7 Fuzzy systems in the PLC
26.07.2007
Standard guide
The PLCopen contains 3 devaluation compatible compliance classes: Base level
Portability level
Full compliance level
4
Contains IL, ST, SFC, CFC (in preparation) a few data types, standard operators, functions, function blocks as well as local variables Data exchange format (8 bit ASCII). Data types with 32 bit strings, Arrays and all functions and operators based on this data type. Here the supreme compatibility degree must exist.
26.07.2007
Functional structure of a PLC Power supply system
Other systems
Operator
Programmer
MMI functions Communication function Check functions
Power supply
Signal executing function
Operating system Operating program
Executing function
Data
Interface function to sensors and actuators
5
process
26.07.2007
Communication functions
Ethernet, RS232, Modem Other systems
Server
ADS OCX, ADS DLL, TwinCAT OPC
MMI functions Communication function Check functions ADS/AMS router
6
Operator Programmer
Forcen, Breakpoints, single step, System Manager, Scope View
26.07.2007
Signal executing function
Compiled PLC project, selfdefined server
Signal executing function
Operating function
Win NT, 2000, XP
Operating system Operating program
Data
PLC Server 1, PLC Server 2, PLC Server 3, PLC Server 4, NC Server, Cam Server
ADS-, I/O process image
7
26.07.2007
Interface function between sensors and actuators
Interface function between sensors and actuators Copy rule DP RAM PA PLC
A
E
Actuators and sensors DP/PA
F-Sensor 8
F-FieldDevice
F-Actuator 26.07.2007
Overview
Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
9
26.07.2007
Software model
Configuration Resource
Resource Task2
Task1 Program
Main
Program Motion FB
Task1
Task2
Program
Program
FB
FB
FB
FB
Global and direct addressed variable
access paths
10
26.07.2007
Software model Example Example PC PLC with 1 run time und zwei Task 1 BC900 (Ethernet Controller) Configuration
Resource PC Task2
Task1 Program
Resource BC9000
Main
Task1
Program Motion FB
FB
Program FB
FB
Global and direct addressed variable Mapping in the TwinCAT System Manager
access paths
11
26.07.2007
Overview Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
12
26.07.2007
Identifier
Identifier serves to the individual name assignment for variables, data types, functions...
• The identifier begins with a letter or a underscore • Followed by numbers, letters and underscore • No difference between capital letters and small letters Not allowed • Special characters (!,“,§,$..) • Blank character • Sequential underscores • mutated vowel
13
26.07.2007
Prefix
Prefixes are not specificated, but they make the handling of the identifier easier. Here some suggestions:
Hungarian notation: Write part words together. The first letter of a part word must be a capital letter.
b – Boolean r – Real s - String ST_ - Declaration of structures st - Initialisation of structures FB_ - Declaration of function blocks fb – Initialisation of function blocks M_ - Declaration of methods
14
bEndschalterLinks rSollPosition sRxDaten ST_MotorDaten stM1Parameter
(declaration) (instance)
FB_Ueberlast fbM1Ueberlast
(declaration) (instance)
26.07.2007
Key words and comments
Key words are preset indentifer by the IEC61131-3. They are fixed components of the syntax and must not be used for other purposes. TRUE, FALSE, AND, FUNCTION,...
Using the option Auto format, the keywords are written in capital letters.
15
The comments are limited with the characters (* at the beginning and *) at the end. Comments can be placed there, where blank characters are allowed. Exception: inside character string literals. (*digital inputs*) bStart AT%IX0.0:BOOL;(*Machine start*) (*analog inputs*) TemK1 AT%IW10(*Byte 10-11*):WORD;
26.07.2007
Overview Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
16
26.07.2007
Data types
Data types describe memory locations resp. appoint their features.
Value type Data width Initial value Value range Type
value
(Part) STRING
µ
SINT
-75
USINT
181
Memory
1 17
(WORD) (2 Byte) (0) (0..65535)
0
1
1
0
1
0
1 26.07.2007
Elementary data types
Type
ANY-Type
Key word
Data width (Bit)
Initial
Value range
Boolean
ANY_Bit
BOOL
1
FALSE
TRUE/FALSE
Bit string(8)
BYTE
8
0
0..16#FF
Bit string(16)
WORD
16
0
0..16#FFFF
Bit string(32)
DWORD
32
0
0..16#FFFF_F FFF
SINT
8
0
-27...27-1
Integer
INT
16
0
-215...215-1
Double integer
DINT
32
0
-231...231-1
Unsigned short integer
USINT
8
0
0...28-1
Unsigned integer
UINT
16
0
0...216-1
Unsigned double integer
UDINT
32
0
0...232-1
Short integer
ANY_Num
18
26.07.2007
Elementary data types
Type
ANY-Type
Key word
Data width (Bit)
Initial
Value range
Slide point
ANY_Real
REAL
32
0.0
-1.18*10-38.. 3.4*1038
LREAL
64
0.0
-2.22*10-308.. 1.798*10308
DATE (D)
32
D#1970-01-01
Time of day
TIME_OF_DAY (TOD)
32
TOD#00:00
Date time of day
DATE_AND_TIME (DT)
32
DT#1970-0101-00:00
Long slide point Date
ANY_Date
time
ANY_Time
TIME
32
T#0ms
Sequential characters
ANY_String
STRING
(80+1)*8
‚‘
19
TOD#00:00.. TOD#23:59
26.07.2007
String
A STRING type variable can contain any string of characters. The size entry in the declaration determines how much memory space should be reserved for the variable. It refers to the number of characters in the string and can be placed in parentheses or square brackets. If no size specification is given, the default size of 80 characters will be used.
20
VAR strVar :STRING(3); lenVar: INT; sizeVar: INT;
Strings are zero terminated, that means the last character of a string is always zero. Each character inside a string needs one byte.
END_VAR
26.07.2007
Special characters
If you want to add a special character into a string, you have to begin with a $character.
A CR 1 0 0 (*Str. Abschluss*)
21
Special Characters character
description
$$
dollar signs
$‘
Single quotation mark
$L or $l
Line feed
$N or $n
New line
$P or $p
Page feed
$R or $r
Line break
$T or $t
Tab
26.07.2007
ASCII CHR
If a character in a program ought to be converted to an ASCII character, two procedures are allowed: 1.
Indirectly, by interpreting the data memory different.
2.
Directly via the provided function block. ASC and CHR are both included in the library ChrAsc.lib.
(Component of the Comlib)
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26.07.2007
Variables declaration el. data types
A variable owns a name, behind which a value (number, string, date) hides. The name of the variable is a way description to the declared data. Variables distinguish themselves thereby, that their content can be changed to the run time.
Identifier
Data type
Initial value
bStellerUntenLinks:BOOL:=TRUE;
The physical logical storage location of the variable is not known by the operator (unlocated)
The degrees of freedom and the restrictions at the assignment of the identifiers can be seen on the slides identifier and prefixes. 23
26.07.2007
Variables declaration el. data types At the declaration of the variables it´s possible to link the name with an explicit specified address. For the mapping of the inputs and outputs to the symbolic variables, the locating of variables is essential.
AT
Identifier
AT
Identifier
Address
:
%I
X
%Q
B
%M
W D
Bit
Byte
Data type ; Data type
Byte
These variables own a unique address (located)
bStellerUntenLinks AT%IX0.0:BOOL:=TRUE; From TwinCAT 2.8 the addressing can be done automatically. Then the program works with not completely located variables. bStellerUntenLinks AT%I*:BOOL:=TRUE; 24
26.07.2007
Overview
Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
25
26.07.2007
Validity range
Local variables are limited on the block, in which they were declared.
Global variables are known in each block inside a project.
Key words
Key words
VAR ..
VAR_GLOBAL ..
END_VAR VAR_INPUT ..
END_VAR VAR_CONFIG ..
END_VAR VAR_IN_OUT ..
END_VAR
END_VAR VAR_OUTPUT .. END_VAR
26
26.07.2007
Access via the located variables
From program A is a direct access by address %MB2 to the local declared variable ‚locVar‘ in program B possible.
Project Machine PROGRAM A
PROGRAM B
VAR
VAR locVar AT%MB2:WORD; END_VAR
END_VAR
LD %MB2
27
26.07.2007
Overlapping in the validity range
Project Machine VAR_GLOBAL Var1:WORD; END_VAR
PROGRAM A VAR Var1 :WORD; END_VAR
As shown in the example on the left, there is an overlapping in the validity range. In this case, the local declared variable Var1 is loaded into the accumulator. The compiler generates no warning for this overlapping.
LD Var1
28
26.07.2007
Attributes Attributes can be used to define special features of variables. Examples: The variable(s) should be stored at the shutdown of the PLC, to be reloaded at the new start. VAR RETAIN Zaehler:UINT; END_VAR VAR PERSISTENT Zaehler:UINT; END_VAR Initial values, the variables should be allocated with a special value at the PLC start or reset. VAR AccelerationTime : TIME := T#3s200ms; END_VAR 29
26.07.2007
Attributes (constants)
Projekt Maschine VAR_GLOBAL CONSTANT END_VAR PROGRAM A VAR CONSTANT END_VAR
30
If you want to use a mathematic, construction, or machine constant, you have to complete the regular key words VAR_GLOBAL .. END_VAR with the key word CONSTANT. This completement can also be used with local keywords. The state of these identifier is read. VAR_GLOBAL CONSTANT pi:REAL:=3.141592654; END_VAR
26.07.2007
Overview
Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
31
26.07.2007
POU program organisation units
In the IEC61131-3 exists under the main generic term three POUs: Programs Function blocks Functions The organisation POU is replaced by the task configurator.
The data POUs are replaced by multi-dimensional fields (ARRAY‘s).
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26.07.2007
POU program organisation units
Each POU consists of a declaration part and a body. The declaration part is the same in each IEC programming language. The local variables of the block are declared there.
The body is written in one of the IEC programming languages which include IL, ST, SFC, FBD, LD or CFC.
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PROGRAM PRG Program PRG •
Call by a task (TwinCAT: One programm calls another)
•
calls : FB‘s, Functions, (Programs)
•
Local variable : static, i.e. the local data are available at the next cycle.
•
Inputs: mostly 0, but VAR_INPUT possible
•
Outputs: mostlys 0, but VAR_OUTPUT possible
•
Transfer by reference: VAR_IN_OUT also possible
•
Debug: The local data are directly visible in the online mode of the PLC Control
•
Using: Main programms, main, hand, automatic....
34
26.07.2007
Function block FB
Function block FB •
Called by programs or other FB´s
•
calls : FB‘s, functions,
•
Locale variable : static, i.e. the local data are again available at the next cycle. At multiple call multiple instances (mulitply). Each FB call can have 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
•
Debug: In the online mode of PLC Control, the instance of the according call has to declared. After this, the local data are visible for each call.
•
Using: multiple used function blocks, which need an own data range each. Multiple sequences....
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Create an instance
FB FUNCTION_BLOCK A VAR _INPUT Var_IN :WORD; END_VAR VAR _OUTPUT Var_Out :BYTE; END_VAR VAR Var1 :WORD; Instanz_1: B; END_VAR
LD Var1 CAL Instanz_1
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PROGRAM MAIN VAR Instanz_1 :A; Instanz_2 :A; Instanz_3 :B; END_VAR
PRG
CAL Instanz_1 CAL Instanz_3
FB FUNCTION_BLOCK B VAR_INPUT X :REAL; END_VAR VAR _OUTPUT Y :REAL; END_VAR
Instanz_1 Var_In :WORD; Var_Out :BYTE; Var_1:WORD; Instanz_1 X :REAL; Y :REAL;
Instanz_2 Var_In :WORD; Var_Out :BYTE; Var_1:WORD; Instanz_1 X :REAL; Y :REAL;
Instanz_3 X :REAL; Y :REAL;
26.07.2007
Function FC Function FC •
called by: programs, function blocks and other functions
•
calls: functions
•
Local variable : temporary, i.e. the local data are only available for the operating time of the function. Afterwards this data range is used by other functions.
•
Inputs: 1,2,3........ VAR_INPUT
•
Outputs: exactly 1!, but structure varaibale possible. The output name is at the same time the name of the function.
•
Except for TwinCAT: VAR_IN_OUT possible,
•
Debug: The local variables are visible with „???“ in the online mode of PLC Control, because these variables are multiple used by all functions in the cycle, and the monitoring (debug) takes place at the cycle bounds. Hepl: program development with breakpoints Breakpoints
•
Using: algorithms, at which the result is available after a pass. Scaling, compare......
37
26.07.2007
FC Specials
From TwinCAT 2.8: The return value can be defined directly if a new function is created.
Function name
Return value The name of the „output“ is scale.
Inputs Local variables are only valid for the operating time of the function
38
Scale can be used as local variable inside the function(Write/Read)
26.07.2007
Overview Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
39
26.07.2007
TwinCAT System Service
The TwinCAT System Service operates as Windows NT service in the local system account. In this way, the TwinCAT System Service is started by Windows NT before a user has logged on. As an activity symbol, the TwinCAT System Service incorporates its icon into the task bar of the desktop. In addition, the colour of the icon indicates the state of the TwinCAT system. TwinCAT stopped TwinCAT starting. TwinCAT running. TwinCAT Config Mode
The TwinCAT System Service is primarily responsible for starting and stopping the TwinCAT run time system. It loads all configured servers and initialises them during the TwinCAT system start. . 40
26.07.2007
TwinCAT System Service
The event display is a programm to moniotor the events in the system. The event logging service starts automatically, if you execute Windows NT.
The TwinCAT I/O subsystem can be reset via the TwinCAT System Service. For this, the corresponding function must be selected in the context menu. The reset applies to all connected field bus systems. 41
26.07.2007
Multitasking
TwinCAT possesses more than 62 different tasks. The default settings can use preset profiles or change the priority individually.
42
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Assigning the computing power Real time operation of PLC software in the classical PLC. Read inputs Write outputs
Operate program Win NT & HMI Interface
PLC cycle PLC cycle Real time operation of PLC software (1 task) on a PC with windows NT.
PLC cycle 43
PLC cycle
t
t 26.07.2007
Overview
Contents
Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
44
26.07.2007
Real time
Many industrial applications demand a guarantee, that, clearly predictable and reproduceable, the system load reacts sufficient fast to the process event in a defined time. The real time is very important for the digital control. The sampling of an analog signal (actual position) with a PC should have absolute constant distances between two measurements. Each part process requires different reaction times. Because of this, several part processes with different features and different reaction times can be created in one automation task. If several tasks want to access the CPU simultaneously, the IEC 61131-3 defines two procedures: 1. Preemptive (interruptible execution) multi tasking (TwinCAT) 2. Non preemptive (not interruptible execution) multi tasking
45
26.07.2007
Real time operation
The real time operation will be achieved with deterministic time slices. The width of the time slices can be chosen in steps: (1000µs ... 50µs). The default setting is 1ms.
The time slices will be kept with an accuracy of ± 15µs (Jitter). Device with the lowest priority goes to the waiting loop and waits until the CPU is free.
With the begin of a new time slice, the software devices (PLC, NC) will be executed with priority control.
46
- 15µs +15µs
26.07.2007
Real time
The TwinCAT real-time system can be configured via the context menu of the TwinCAT System Service. Length of the time slice
Processor time can be assigned to the TwinCAT real-time system via the linear regulator in the figure above. On a time basis of 1 ms, this means that TwinCAT has a maximum of 800µs available each millisecond. When the TwinCAT real-time system switches to its idle task, the processor is returned to Windows NT. The bar in the linear regulator dis-plays the current utilisation level of the real-time system. The display is averaged over 256 cycles (ms).
In this case, the current and maximum latency times in the real-time sys-tem are shown. The time by which the central system tick arrives too late is measured. 47
26.07.2007
Real time operation Cyclic PLC task e.g. 10ms
20ms
10ms
30ms
0ms
40ms
Refinement: Behavior under TwinCAT base cycle 1 ms
80% TwinCAT 0ms
80%
W
TC
1ms PLC
PLC
W
80% W
2ms
Time slice for Windows 3ms
Time slice for TwinCAT PLC program cyclic task
If TwinCAT does not need the (full) reserved time slice, the scheduler provides this computing power to windows. 48
26.07.2007
Real time operation
PLC tasks and drive control will be executed deterministically with multiple tasking.
Real time operation of a PLC program and NC control with a PC NC
PLC program
Win NT & HMI Interface
1
1
2
e.g.: 1ms
NC cycle
(e.g. 1ms)
SPS cycle 49
1‘
3
2
4
2‘
2ms
3ms
4ms
NC cycle
NC cycle
NC cycle
(e.g. 2ms)
3 5ms
t t
PLC cycle 26.07.2007
Real time operation
The smaller the time slice, the shorter the reaction time of the highest priority task. This has the consequence that the software devices must be fairly often interrupted. If a device is interrupted, the program stack has to be safed. This has the consequence that the recopy expense rises. TwinCAT and the operating system are equal. For the operating system, calculating capacity is given regularly. The switch to the operating system takes place at the earliest, as soon as all TwinCAT devices complete the processing, and at the latest at the CPU limit.
50
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Task + POU´s -> Create a new project
Before a new project starts, the following questions have to be checked: 1. What is the target platform, i.e. the device the user wants his program to run. TwinCAT offers three different platforms. Soft SPS (IPC)
Hard SPS (BCXXX0) 51
26.07.2007
Create a new project
2. In which distances and under which circumstances shall the PLC program be processed? The IEC 61131-3 defines the task as a element of the execution control, which is able to call several programs to execute. At the configuration of the task one of the variants „cyclic“ and „event“ can be chosen. TwinCAT only supports the „cyclic“ variant.
It´s possible to create an event driven task from a cyclic task. For this, the program call must depend on an event.
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26.07.2007
Create a new project
Priority of the task. The value range (0-3) is an offset on the default value 25 for the first run time. Each run time possess maximum to four different tasks.
The task name is an identifier. Respectively the rules for the identifier obtain.
The interval time is always a multiple of the time slice. 53
26.07.2007
PLC Control Symbol bar
File
Project
Element
new
Start
Cut
open
Stop
Copy
safe
Single step
Insert
Breakpoint
Find
Log in
Find next
The field for the variables depends on the selected IEC language.
Log off
PLC Control 54
26.07.2007
Main program
The task is a trigger mechansim. A program is required to execute logical operations. The task calls one program. If an instance of a function block is needed, it can only be called from a program.
The features of an POU can be defined with this dialog. The name is an identifier. Respectively the rules for the identifier obtain. The type of the POU depends on the problem. The language of the POU should be used according to the problem.
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Program
A program is a POU which returns several values during operation. Programs are recognized globally throughout the project. All values are retained from the last time the program was run until the next.
Programs can be called by programs and function blocks. A program call in a function is not allowed. If a POU calls a program, and if thereby values of the program are changed, then these changes are retained the next time the program is called, even if the program has been called from within another POU.
56
26.07.2007
Overview
Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
57
26.07.2007
Derivated data types (Variable II)
The user can create own data types on the base of elementary data types or already created data types. The new created data types are visible in the whole project. They begin with the keyword TYPE and end with END_TYPE.
Parent type
Name
Data type
New value
Derivation
58
Name
Data type
Initial value
Range
Initial value
Range
h e i r
26.07.2007
References (Alias Types) (Variable II)
You can use the user-defined reference data type to create an alternative name for a variable, constant or function block. Create your references as objects in the Object Organizer under the register card Data types. They begin with the keyword TYPE and end with END_TYPE.
Syntax: TYPE :; END_TYPE
Example: Ads_Net_ID TYPE Net_ID:STRING(23); END_TYPE
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26.07.2007
Enumeration (Variable II)
Enumeration is a user-defined data type that is made up of a number of string constants. These constants are referred to as enumeration values. Enumeration values are recognized in all areas of the project even if they were locally declared within aPOU. It is best to create your enumerations as objects in the Object Organizer under the register card Data types. They begin with the keyword TYPE and end with END_TYPE. Syntax: TYPE :( ,, ...,); END_TYPE Beispiel: 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
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You may not use the same enumeration value more than once. 26.07.2007
Enumeration (Variable II)
The can take on one of the enumeration values and will be initialized with the first one. These values are compatible with whole numbers which means that you can perform operations with them just as you would with INT. You can assign a number x to the . If the enumeration values are not initialized, counting will begin with 0. When initializing, make certain the initial values are increasing. The validity of the number will be reviewed at the time it is run.
VAR WochenTag:Woche; END_VAR WochenTag:=3;
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26.07.2007
Structure declaration (Variable II)
form
Structures are self defined data types. They are important aids for managing the process data.
Pers_Data Name:
Furthermore the structures are suited for capsulated data transfer to function blocks.
Firstname:
Age:
Address:
TYPE Pers_Data : STRUCT Name: STRING(25); Firstname: STRING(25); Age:USINT; Address: STRING(55); END_STRUCT END_TYPE 62
Structures can be used like single element variables.
Identifier for the new data type Identifier : parents data type ■ ■ ■
26.07.2007
Structures Instances (Variable II) P1
Name:=‚Müller‘ Firstname:=‚Peter‘ Age:=32 Address:=‚Postweg 34‘
P1 K2
P3
Name:=‚Koschnik‘ Firstname:=‚Heinz‘ Age:=37 Address:=‚Domplatz 10‘
P3
VAR P1, P3 : Pers_Data; END_VAR VAR_OUTPUT K2 : Pers_Data; END_VAR ■ ■ 63
VAR_INPUT Employees: Pers_Data; END_VAR Name_total:=CONCAT(P3.Firstname, P3.Name) (*Heinz Koschnik*)
26.07.2007
Overview
Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
64
26.07.2007
Arrays (Variable II)
Arrays describe lists resp. data arrays. All elements in the arrays are from the same type. Arrays can also exist of own data types (structures). One- , two-, and three-dimensional arrays are possible. VAR Feld_1 :ARRAY[1..10] OF BYTE; Feld_2 :ARRAY[1..10, 2..5] OF UINT; :ARRAY[1..10] OF DINT; END_VAR
one-dimensional two-dimensional Feld_3 three-dimensional
It´s possible to put a data array to a direct addressed memory position VAR Feld_1 AT%MB100:ARRAY[1..10] OF BYTE; END_VAR
Access to the sub-elements of a data array Feld_1[2] := 120; (* explicit access*) Feld_2[i,j] := EXPT(i,j); (*indicated access*) 65
26.07.2007
Array one-dimensional example with initialisation (Variable II) One-dimensional
Identifier
Field
Data type
Initial value
DBZeiten :ARRAY [0..6] OF TIME:= T#1s, T#2s, T#1s, 4(T#0s); Faktor
Wert
0
1
2
3
4
5
6
T#1s
T#2s
T#1s
T#0s
T#0s
T#0s
T#0s
Access: VAR
The field length can be done explicit or with the aid of constants. A dynamic change of the field size is not possible.
WertAusArray : TIME; END_VAR
WertAusArray := DBZeiten[1]; 66
26.07.2007
Array two-dimensional example with initialisation (Variable II)
To assign for example support points, an array is well qualified.
Identifier
Field
Data type
Initial value
Supportpoint:ARRAY [0..1, 0..6] OF REAL:= 0, 1.7, 2, 4(3.33), 6, 6(1.2); Factor
0
0
1
2
3
4
5
6
0
1.7
2
3.33 3.33 3.33 3.33
Value
Access: VAR WertAusArray : REAL; END_VAR
1
6
1.2
67
1.2
1.2
1.2
1.2
1.2
WertAusArray := Supportpoint[1 ,0];
26.07.2007
Array initialisation more clearly with comments (Variable II)
Example: Drive jobs for an axis
Drivejob:ARRAY [0..3, 0..1] OF LREAL:= (* target position,
velocity *)
(*Job 0*)
20.0,
30.0,
(*Job 1*)
33.75,
30.0,
(*Job 2*)
45.0,
30.0,
(*Job 3*)
70.75,
30.0;
68
26.07.2007
Array three-dimensional example with initialisation (Variable II)
Identifier
Array
Datatype
Initial value
Supportpoint :ARRAY [0..2, 0..1, 0..2] OF UINT:= 0,1,2,3,4,5, 10,11,12,13,14,15, 20,21,22,23,24,25
2 1 0 1
3
1
4
0
0
1
2
23 24 25
0
20 21 22
13 14 15
5 0
1
10 11 12 0
1
2
Access: VAR ValfromArray : UINT;
0
1
2
END_VAR ValfromArray
:=
Supportpoint[ 2,0,1 ];
0
1
2 69
26.07.2007
Exceed bounds (Variable II)
A dangerous state can arise in the PLC program, if an access to a range outside the data field takes place.
VAR Feld_1 :ARRAY[1..10] OF BYTE; Feld_2 :ARRAY[1..10, 2..5] OF UINT; Feld_3 :ARRAY[1..10] OF DINT; END_VAR i:= 9 Feld_1[i+2] := 120;
9
Feld_1[9];
0
Feld_2[1,2];
120
70
26.07.2007
Overview Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Check bounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
71
26.07.2007
Check Bounds (FUN)
If you define a function in your project with the name CheckBounds, you can automatically check for outof-range errors in arrays.
FUNCTION CheckBounds :INT VAR_INPUT I,L,U : INT; END_VAR
IF I< L THEN Error case
CheckBounds := L;
ELSIF I > U THEN Error case Limited value
i Min Max
CheckBounds := U;
ELSE „OK“ case
CheckBounds := I;
END_IF
72
26.07.2007
Inserting Check Bounds 1(FUN)
CheckBounds can be copied with „Copy Project“ from another PLC project to the current project ( e.g. training project). Checkbounds can also be created or written directley.
73
26.07.2007
Inserting Check Bounds 2(FUN) So that CheckBounds is recognised by translating, the following may NOT be changed: -Name and type of the inputs I,L and U -Name (CheckBounds) and return value (INT). -In the function can be edited freely. At application of own local variables (e. g. error counter, instances of FBs) is to be considered that these are only temporary (at functions). Such a variable has to be declared (in this case) under the global variables.
74
26.07.2007
Check Bounds (FUN) mode of operation FUNCTION CheckBounds :INT
Program (* User*) VAR arrVar:ARRAY[0..3] OF INT index :INT END_VAR
VAR_INPUT I,L,U : INT; END_VAR Automatical call
IF I< L THEN CheckBounds := L; ELSIF I > U THEN CheckBounds := U;
index:=2; arrVar[Checkbounds[2,0,3]:=100;
Access at 2 ->ok
ELSE
CheckBounds := I; END_IF FUNCTION CheckBounds :INT
index:=index+2
VAR_INPUT I,L,U : INT;
arrVar[Checkbounds[4,0,3]:=100;
END_VAR IF I< L THEN CheckBounds := L;
Checkbounds returns 3, the access is limited to the maximum index 75
ELSIF I > U THEN
CheckBounds := U; ELSE CheckBounds := I; END_IF 26.07.2007
Note: Further Checker functions
From TwinCAT 2.8 the following further Checker functions are possible:
Check division by 0 CheckDivByte CheckDivWord CheckDivDWord CheckDivReal
Check value range CheckRangeSigned CheckRangeUnsigned (see Appendix)
76
26.07.2007
Combination Structures and Arrays (1) 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; (*Pump ?*)
Declaration of the arrays :
Positions :ARRAY[0..100] OF DrillPos; 77
26.07.2007
Combination Structures and Arrays (1)
Access to „Drillpos 55“: Access: MoveXAx (*FB Instance*) ( Execute:= Position:= Velocity:= Acceleration:= Deceleration:= Jerk:= Direction:= Axis:= );
78
TRUE, Positions[55].XPos , Positions[55].FeedrateX Positions[55].AccelerationX, Positions[55].DeccelerationX, Positions[55].JerkX, ........., .............,
26.07.2007
Overview
Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Check bounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
79
26.07.2007
ST Structured Text operators in the order of their binding strength:
Operation
Symbol
Binding strength
Put in parentheses Function call Exponentiation Negate Build. complements Multiply Divide Modulo Add Substract Compare Equal to Not Equal to Bool AND Bool XOR Bool OR
(expression) Function name (parameter list) EXPT NOT * / MOD + ,= = AND XOR OR
Strongest binding
80
Weakest binding
26.07.2007
ST Structured text: Overview about Instructions
Instruction
Example
Assignment :=
PosWert := 10;
Callin a function block
Ton1(IN:=Start, PT:=T2s); Output:= Ton1.Q
RETURN
RETURN;
IF
See the following pages
CASE FOR WHILE REPEAT EXIT Empty instruction
81
;
26.07.2007
IF Instruction
Is needed to branch in a program depending on conditions.
Keywords:
IF With the IF instructions it´s not possible to jump back in the PLC cycle.
THEN
ELSIF ELSE END_IF
„GOTO“ is not available
e.g.:
82
26.07.2007
IF Instruction (1)
Condition IF Condition THEN Instruction block; END_IF
No
Yes
Instruction block
83
26.07.2007
IF Instruction (2)
Condition IF a>b THEN Instruction block A; ELSE Instruction block B; END_IF
84
No
Yes
Instruction block A
Instruction block B
26.07.2007
IF Instruction (3)
Condition 1 No Yes Condition 2 No Yes Condition 3 No Yes Instruction block A
Instruction block B
85
Instruction block C
IF Condition1 THEN Instruction block A; ELSE IF Condition2 THEN Instruction block B; ELSE IF Condition3 THEN Instruction block C; ELSE Instruction block D; END_IF END_IF END_IF
Instruction block D
26.07.2007
IF Instruction (4)
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
86
Instruction block B
Instruction block C
Instruction block D
26.07.2007
IF Instruction (5) What can the „BOOLEAN EXPRESSION“ be ?
Conditions : •BOOLEAN Variable •Comparison •Function calls •Call FB Instances •NO FB call!
87
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
26.07.2007
CASE Instruction
CASE Selection criterion OF 1:
Instruction 1
2,4,6:
Instruction 2
7..10 :
Instruction 3
Selection criterion = 1
Selection criterion = 2 Or 4 or 6
No
Selection criterion = 7 Or 8 or 9 or 10?
Yes
No Yes
.. ELSE
No
Default Instructions
Yes
Instruction 1
Instruction 2
Instruction 3
Default Instructions
END_CASE;
Two same values mustn´t be available at the listing. 88
26.07.2007
CASE Instruction Integer Selector Value with Enum types
CASE State OF Enum Typ: TYPE Schritte : ( INIT:=0, START, AUTOMATIK, ENDE); END_TYPE
INIT:
instructions;(*State=0*)
START:
instructions;(*State=1*)
AUTOMATIK:
instructions;(*State=2*)
ENDE:
instructions;(*State=3*)
END_CASE
If the integer selector variable state is declared as enum, the value of the variable is visible in the online mode.
VAR State:Schritte; (* State:INT also possible*) END_VAR 89
26.07.2007
CASE Instruction Integer Selector Value with constants
VAR CONSTANT Step1 : INT:= 0; Step2 : INT:= 1;
CASE State OF
Step3 : INT:= 2;
Step1:
instructions;(*State=0*)
Step4 : INT:= 3;
Step2:
instructions;(*State=1*)
Step3..Step4:
instructions;(*State=2 oder 3*)
END_VAR
END_CASE VAR State:INT; END_VAR
90
26.07.2007
CASE Instruction proposal for a Statemachine TYPE Steps : ( INIT:=0, START, AUTOMATIC, END); END_TYPE Instruction for the step
CASE State OF
(Actions)
INIT:
Q0:=TRUE; IF Transition THEN state := START; END_IF
START:
Q1:=TRUE;
„step enabling condition“ (Transition)
IF Transition THEN state := AUTOMATIC; END_IF
Step
AUTOMATIC: Q2:=TRUE; IF Transition THEN state := END; END_IF END:
Q3:=TRUE; IF Transition THEN state := INIT; END_IF
END_CASE 91
26.07.2007
Repeat Instructions
The process flow requires the multiple handling of exactly the same program sequences, whose quantitiy is known at the run time.
If a continuous loop is executed this does not impair the start of the time slice (real-time). Tasks that will have a higher priority are still executed on time. Tasks that will have a lower priority are not longer executed.
Disadvantage of loops: During faulty programming, many repetitions take place infinitely.
Forced switch to Win NT
1
1
2
e.g.: 1ms
2ms
92
1‘
3 3ms
1‘‘
Begin of a new time slice
4 4ms
1‘‘‘
1‘ 5ms
26.07.2007
Loops (Overview)
All loops can be ended with the EXIT instruction, regardless of the break-off condition.
Expression FOR
Work flow
n cycle fix
SINT/ INT / DINT
Pre repel
Yes
WHILE
BOOL
Pre repel
No
REPEAT
BOOL
Post repel
No
93
26.07.2007
FOR loop
cycle n At the beginning of the loop, the variable i is defined as start value (see example). The variable in incremented or decremented in each cycle depending on the step width (value after the keyword BY) If i exceeds the end value (after TO), the loop is not longer processed.
Start i:=Start value
i >End value
Yes
No Instruction block
I:= i+ Step width
FOR i:=1 TO 12 BY 2 DO Field[i]:=i*2;(*instruction*) END_FOR 94
cycle n 26.07.2007
WHILE loop cycle n The instruction block of a WHILE loop is executed as long as the boolean expression supplies TRUE . The exit condition contains variables which can be changed in the instruction block. If the boolean expression is FALSE at the beginning, the instruction block of the WHILE loop is not processed.
i:=0; WHILE i100 END_REPEAT 96
Yes
Boolean expression
No
cycle n 26.07.2007
FB calls in ST
VAR TON1:TON; END_VAR TON1 (IN:= NOT TON1.Q , PT:=T#1s ); Q0:= TON1.Q from TwinCAT 2.8 :
TON1(IN:= NOT TON1.Q, PT:=T#1s , Q=>Q0 );
97
26.07.2007
FB calls in ST explanation: Create instance of FB
VAR TON1:TON; END_VAR
Call with instance name
TON1 (IN:= NOT TON1.Q , PT:=T#1s ); input parameters Scan output
Q0:= TON1.Q
Not possible: FB can have several outputs:
Q0:=TON1(IN:= NOT TON1.Q, PT:=T#1s); 98
26.07.2007
FB calls in ST (alternative)
VAR TON1:TON; END_VAR TON1.IN:= NOT TON1.Q , TON1. PT:=T#1s; TON1(); Q0:= TON1.Q
99
26.07.2007
FB calls in ST (alternative) explanation
Declaration
VAR TRANSFER ONLY INPUT PARAMETER . This is
NO FB CALL!!!!!
TON1:TON; END_VAR
TON1.IN:= NOT TON1.Q ; TON1. PT:=T#1s; TON1(); scan output 100
FB CALL
Q0:= TON1.Q; 26.07.2007
FC calls in ST
Result:=Scale
(x:=input, xug:=0.0, xog:=32767.0, yug:=0.0,yog:=100.0);
(* equal:*) Result:=Scale
(input, 0.0, 32767.0, 0.0, 100.0);
(* equal :*) Result:=Scale
101
( x:= xug:= xog:= yug:= yog:= );
input, 0.0, 32767.0, 0.0, 100.0
26.07.2007
FC calls in ST explanation:
Result := Scale (x:=input, xug:=0.0, xog:=32767.0, yug:=0.0,yog:=100.0);
Result
CALL
(* equal:*) Result:=Scale ( x:= xug:= xog:= yug:= yog:= ); 102
Input parameters
input, 0.0, 32767.0, 0.0, 100.0
26.07.2007
Overview Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
103
26.07.2007
SFC Sequential Function Chart
Step N
Transition Following step
N
Action
Qualifier
• Only one step is active at a time • The condition to change from one step to another is the transition. • In the action must be programmed what should be executed during the active step.
Action
Transition Action,
Qualifier
104
Can be written in Structured Text, Instruction list, Ladder Diagram, Function Block Diagram and in Sequential Function Chart .
26.07.2007
Steps
Initial step active at the start Init N
Transition
Action
„Normal“ Step“
Step1 N
Action
• The activity of a step can be requested with Stepname.X. • The duration of the activity of a step can be requested with Stepname.T . • Both are components of a structure, which are created automatically from PLC Control. At the programming only the stepname has to be defined. • Stepname.X and Stepname.T are local variable and can only be read.
Transition
105
26.07.2007
Actions Transition Transition Step1 N
Action
Step1 N
bOutput
Transition Transition
Action, can be programmed in -> Structured Text, -> Instruction List, -> Ladder Diagram, -> Function block diagram, CFC/FBD
Action, can be a variable of type BOOL. The variable is TRUE by activating the the step and FALSE by leaving the step.
-> Sequential Function Chart
106
26.07.2007
Actions, several allowed per step
Transition
Step1
107
N
bOutput
P
STAction
N
LDAction
R
FBDAction
26.07.2007
Steps /alternative branches
• Only one branch can be active.
Init N
Action
• Because only the left or the right branch is important, two transitions are necessary before the combination. Transition
Transition
Stepa
Stepb N
Transition
108
Action
N
Action
Transition
26.07.2007
Steps / alternative branches
• The branches needn´t be symmetrical.
Init N
Action
Transition
Transition
Stepb N
Stepa N
Action
Action Transition Stepc
Transition
N
Action
Transition
109
26.07.2007
Steps /alternative branches
• Branches can be skipped. Init N
Action
N
Action
Transition
Stepa Transition
Transition
110
26.07.2007
Steps /simultaneous branches
•Two branches are processed “simultaneous”.
Init N
Action Transition at the beginning of the simultaneous branch
Transition
Step_a
Double line, symbolises the simultaneous branch
Step_b N
Transition
111
Action
N
Action
Transition at the „end“
26.07.2007
Steps /simultaneous branches
• Simultaneous branches needn´t be symmetrical.
Transition
Step_b N
Action
N
Action
Transition
Step_a N
Action Step_c
Transition 112
26.07.2007
Transitions
A Transition must be of type „BOOL“. Possibilities: Init N
• BOOLEAN Variable
Action
• ST Instruction • „programmed“ Transition
BOOLEAN VARIABLE
bVariable Step1 N
Action ST instruction.
A>B
The result be must be of type BOOL. Note: If the instruction is too long, the display will be shorten automatically.
113
26.07.2007
Transitions Programmed Transitions Init N
Action With this mark it´s only a comment.
A>B
„NOTHING CONNECT“
Step1 N
The result must be of type BOOL and is the transition
Action 001
Comment
A
GT AND
B Hides behind Possible: FBD, LD, IL, ST. Points to programmed transition 114
INPUT0
Limitations: one network, one Instruction sequence, no FB calls. 26.07.2007
Final Scan If a step is left, the processing takes exactly one more cycle. This behaviour can be used for “cleaning”in the action. Example: Reset outputs. Step.X 1 0
Step1
N
Action
t Action processing
1 0
Go on
t 1 Cycle
Following step
001
N
Action
release
AND
Output Step1.X
Transition At the last pass the step.X = FALSE. Thus the variable „Output “ is FALSE . 115
26.07.2007
Final Scan At a certain action the final scan leads to an unwanted behaviour. Step1
N
Action
Step.X 1
TRUE
0 t Action processing
1
Behaviour: Counter := Counter +1;
0 t 1 cycle
1 cycle
(*Counter increases at 2*) Remedy: The step flag is only for one cycle 1: IF Schritt.X THEN Counter := Counter +1; END_IF (*Counter increases at 1*) 116
26.07.2007
Qualifier Controls the action processing after activating a step. N: Non Stored Step
N
Action
Step.X 1 0
TRUE
t Action processing
1 0
N: Non Stored
t 1 cycle
Combination in FBD 001
Step.X
117
Action processing
26.07.2007
Qualifier Controls the action processing after activating a step S: SET Step
S
Action
Step.X 1 0
TRUE
t Action processing
1 0 t 1 cycle
Combination in FBD 001 Step.X
S
SR Action processing
R
118
26.07.2007
Qualifier Controls the action processing after activating a step R: RESET Step
R
Aktion
Step.X 1 0
TRUE
t Action processing
1 0 t
Combination in FBD 001
S
SR Action processing
Step.X
119
R
26.07.2007
Qualifier Controls the action processing after activating a step D: DELAY Step
D T#1s
Action
Step.X 1 0
TRUE
t Action processing
1 0 Delay
t
Combination in FBD 001
Step.X T#1s
120
TON IN Q PT
Action processing
ET
26.07.2007
Qualifier Controls the action processing after activating a step L: LIMITED Step
L T#1s
Action
Step.X 1 0
TRUE
t Action processing
1 0 LIMITED
Combination in FBD
t
Step.X 1
001
AND Step.X T#1s
TON IN Q PT
ET
Action processing
0 t Action processing
1 0 Limit
121
t
26.07.2007
Qualifier Controls the action processing after activating a step P: PULSE Step
P
Action
Step.X 1 0
TRUE
t Action processing
1 0 1 cycle
1 cycle
t
Combination in FBD 001 R_TRIG Step.X
122
Clk
Q
Action processing
ATTENTION: A SECOND FLOW PROCESSES!
26.07.2007
Qualifier, Combinations
SD: Stored and delayed DS: Delayed and stored SL: Stored and time limeted
123
26.07.2007
Overview Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
124
26.07.2007
Sequential Function Chart step diagnosis
VAR SFCEnableLimit:
BOOL;
(*When it has the value TRUE, the timeouts of the steps will be registered in SFCError. Other timeouts will be ignored.*)
SFCInit:
BOOL;
(*When this boolean variable has the value TRUE the sequential function chart is set back to the Init step. The other SFC flags are reset too (initialization).
The Init step remains active, but is not executed, for as long as the variable has the value TRUE. It is only when SFCInit is again set to FALSE that the block can be processed normally. *)
125
26.07.2007
Sequential Function Chart step diagnosis
SFCReset:
BOOL;
(*This variable, of type BOOL, behaves similarly to SFCInit. Unlike the latter, however, further processing takes place after the initialization of the Init step. Thus for example the SFCReset flag could be re-set to FALSE in the Init step.*)
126
26.07.2007
Sequential Function Chart step diagnosis
SFCQuitError:
BOOL;
(*Execution of the SFC diagram is stopped for as long as this boolean variable has the value TRUE whereby a possible timeout in the variable SFCError is reset. All previous times in the active steps are reset when the variable again assumes the value FALSE.*)
SFCPause:
BOOL;
(*Execution of the SFC diagram is stopped for as long as this boolean variable has the value TRUE.*)
SFCTrans:
BOOL;
(*This boolean variable takes on the value TRUE when a transition is actuated. .*)
127
26.07.2007
Sequential Function Chart step diagnosis
SFCError:
BOOL;
(*This Boolean variable is TRUE when a timeout has occurred in a SFC diagram. If another timeout occurs in a program after the first one, it will not be registered unless the variable SFCError is reset first. *)
SFCErrorStep:
STRING;
(*This variable is of the type STRING. If SFCError registers a timeout, in this variable is stored the name of the step which has caused the timeout. *)
SFCErrorPOU:
STRING;
(*This variable of the type STRING contains the name of the block in which a timeout has occurred. *)
128
26.07.2007
Sequential Function Chart step diagnosis
SFCCurrentStep: :
STRING;
(*This variable is of the type STRING. The name of the step is stored in this variable which is active, independently of the time monitoring. In the case of simultaneous sequences the step is stored in the branch on the outer right. No further timeout will be registered if a timeout occurs and the variable SFCError is not reset again.*)
129
26.07.2007
Sequential Function Chart step diagnosis (from 2.8)
SFCErrorAnalyzation:
STRING;
(*This variable, of type STRING, provides the transition expression as well as every variable in an assembled expression which gives a FALSE result for the transition and thus produces a timeout in the preceding step. A requirement for this is declaration of the SFCError flag, which registers the timeout. SFCErrorAnalyzation refers back to a function called AppedErrorString in the TcSystem.Lib library. The output string separates multiple components with the symbol “|”. *)
SFCTip:
BOOL;
SFCTipMode:
BOOL;
(*This variables of type BOOL allow inching mode of the SFC. When this is switched on by SFCTipMode=TRUE, it is only possible to skip to the next step if SFCTip is set to TRUE. As long as SFCTipMode is set to FALSE, it is possible to skip even over transitions.*) END_VAR
130
26.07.2007
Sequential Function Chart process diagnosis
Implicit variable
131
26.07.2007
Sequential Function Chart process diagnosis
• set step attributes for the step to be observed
132
26.07.2007
Online (and per ADS) can be requested
133
26.07.2007
Sequential Function Chart Tipmode
• insert implicit variable:
• effect: SFCTipMode
SFCTip
Transition
effect
TRUE TRUE TRUE FALSE FALSE
FALSE TRUE TRUE TRUE FALSE
TRUE TRUE FALSE FALSE TRUE
Process stays in the current step
134
Change to next step Change to next step Process stays in the current step Change to next step 26.07.2007
Actions also in other IEC languages possible! (POU type : PRG, FB) „Mainprogram“
Action step1
Action step2 135
26.07.2007
Overview
Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
136
26.07.2007
Remanent Flags Variables Attributes
These variables maintain their value, even after a power failure. When the program is run again, the stored values will be processed further. A practical example would be an operations timer that recommences timing after a power failure. A practical example would be an operations timer that recommences timing after a power failure. All other variables are newly initialized, either with their initialized values or with the standard initializations. TwinCAT supports two kind of remanent flags:
RETAIN
137
PERSISTENT
26.07.2007
Retain Persistent Retain
Persistent
To store
To delete
Rebuild all, Reset
Reset all
Possible for
unlocated, located (%M)
Unlocated, located (%I, %Q, %M)
138
26.07.2007
Boot project Power ON
Requirement : It should be possible to automate the loading and the starting of the PLC project after switching on the computer.
The PLC can start independent from the user log on!
139
1
Start NT
2
Start TwinCAT
3
Loading the boot project into the Run-Time
4
Start PLC
Log on
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1&2
1 2
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TwinCAT Auto boot
Auto logon with Win NT
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Create a boot project
Requirement:
1.
The machine should work properly.
2.
The hardware, software and the mappings are correct.
3.
The PLC Control in the status online.
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3&4 Number of run time systems
Enabling for loading the boot project for the run time system 1.
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Enabling for loading and saving the RETAIN data for the run time 1. 26.07.2007
Sourcecode download
1.Goto Project/Options and press the left mouse button. 2.A Window will open 3.Choose the Point Sourcedownload
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Timing for Sourcecode download
1.Implicit at load Every time when you open the PLC Project the Sourcecode will be written down to the controller.
2.Notice at load If the PLC Project changed, you get a message box, when you open the project. 3.Implicit at create boot project. Everytime you create a bootproject, the sourcecode will be transfered to the controller 144
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Timing/Extent for Sourcecode download
1.On demand The Sourcecode will be written down to the controller on demand. Online/Sourcecode download
Extent Sourcecode only •The plc project will be written in the controller All files •The plc project with all libaries will be written tin the controller 145
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Plc project open from the controller
1. You can open the actuell plc projekt direct from the controller 2. Under File/Open you can open the project direct from the plc.
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Were retain and persitent data loaded successfully?
In order to be able to view this data structure, the "PlcSystem.lib" library must be linked in. (Global variable)
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The structure component shows if the persistent/retain data were loaded successfully.
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Meaning of the flags Bit number
Description
0
RETAIN variables: LOADED (without error)
1
RETAIN variables: INVALID (the back-up copy was loaded, since no valid data was present)
2
RETAIN variables: REQUESTED (RETAIN variables should be loaded, a setting in TwinCAT System Control)
3
Reserved
4
PERSISTENT variables: LOADED (without error)
5
PERSISTENT variables: INVALID (the back-up copy was loaded, since no valid data was present)
6
Reserved
7
Reserved
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How can an access to the bootdata flags take place? Because the variable exists in the PLC, (implicit) it can be prompted directly. TcPlcSystem.Lib
IF
GETBIT32(inVal32:=SystemInfo.BootDataFlags , bitNo:=4) THEN errLoadBootData:=FALSE; strBootDataState:= 'PersistentData OK';
ELSIF GETBIT32(inVal32:=SystemInfo.BootDataFlags , bitNo:=5) THEN errLoadBootData:=TRUE; strBootDataState:= 'Error Load PersistentData '; END_IF 149
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Write Persistent Data on demand
With the fuction block „WritePersistentData“ (TcPlcUtilities.Lib) it is possible to initiate the writing of the Persistent Data.
TcPlcUtilities.Lib
The writing takes place at the Shut Down of the PLC (standard). While the function block is busy, the access to the Persistent Variable is not allowed!
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Write Persitent Data on demand, Example:
IF ReqWritePersistent THEN
fbWritePersistent(NETID:='' , PORT:=801 , START:=TRUE , TMOUT:=T#500ms ); IF fbWritePersistent.ERR THEN
fbWritePersistent(START:=FALSE ); ReqWritePersistent:=FALSE; ELSIF NOT fbWritePersistent.BUSY THEN
PLC Runtime
fbWritePersistent(START:=FALSE ); ReqWritePersistent:=FALSE;
Further start after edge
END_IF END_IF
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Internal Libraries
Unnecessary elements: All tasks will be deleted in the task configuration.
Create and test project
All POUs, which are not to belong to thecontents of a library, are removed. All global variables will be deleted.
Delete unnecessary elements of a library
Valid: global constants, self defined data types.
Save as internal *.Lib
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Overview Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
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CheckDivByte
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CheckDivWord
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CheckDivDWord
156
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CheckDivReal
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CheckRangeSigned Variable to be checked
Checker function
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CheckRangeUnsigned Variable to be checked
Checker function
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CheckRangexxx can be done with TYPES
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Overview
Contents Part 1
Part 2
Part 3
IEC 61131-3 Overview
Variables II Structs, Enums
Sequential Function Chart
Software model
Variables II Arrays
Step diagnosis
Identifier
Checkbounds
Appendix
Elementary data types
Structured text
Bootprojects, Data remanence
Variables classes
Checker functions
Block types
Example Step by Step
TwinCAT System Service Timing
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Paint station (PRG)
nozzle 1-3
Start Stop
workpiece
Encoder
Motor
Part exercise: Switch on and off the plant simulate encoder Request marks & switch on the nozzles Safe state when plant off.
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Creating the variables list
Identifier
%I
bStart bStop
%Q
Initial value
Type
AT%IX0.0
False
BOOL
Global
AT%IX0.1
False
BOOL
Global
bMotor
AT %QX0.0
False
BOOL
Global
bDuese_1
AT %QX0.1
False
BOOL
Global
bDuese_2
AT %QX0.2
False
BOOL
Global
bDuese_3
AT %QX0.1
False
BOOL
Global
Marke_1
400
WORD
Local
Marke_2
800
WORD
Local
Marke_3
1200
WORD
Local
Marke_End
1600
WORD
Local
Inc
0
WORD
Local
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Switch on / off the plant
The switches bStart and bStop should be used as push-button. To safe the status, it´s necessary to add a hold element (RS). There are two bistable memorys under the standard function blocks. The dominant input is marked with xxx1.
Set
Set1
Reset1
Reset
Q1
Q1 164
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Simulate encoder & check bounds
The encoder value is incremented each cycle around 1. This is implemented with the operator ADD. Thus a running encoder develop.
It is checked, if the encoder value stands between Marke_1 und Marke_2 . Marke_1 GT Inc LT Marke_2 In this case, the Duese_1 is switched ST
LD Inc ADD 1 ST Inc
LD GT AND LT ST
INC Marke_1 (INC Marke_2) bDuese_1(
IL 165
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Safe state when plant off
If the plant is switched off, all nozzles and the conveyer should be stopped. If the conveyor is stopped, the encoder should became the value 0.
LD
FALSE
ST
bDuese_1
ST
bDuese_2
ST
bDuese_3
ST
bMotor
LD
0
ST
Inc
Load example
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System Manager
By adding a correct project (i.e. the project has been compiled in TwinCAT PLC Control without errors, and afterwards stored), the PLC configuration will be integrated into the current system configuration. The address located I/O variables will be read. By selecting the added PLC project in the tree, the appropriate dialog IEC61131-3 appears on the right side. At I/O configuration, you can configure the fieldbus cards (master) and the boxes (slave) for the given configuration.
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Master cards
Different fieldbus systems. Each fieldbus has several master cards from different manufacturers (Beckhoff FC, Siemens CP, Hilscher CIF). Several different fieldbus master cards can be used parallel.
DP Master
The FC 310X supports the PROFIBUS protocols: PROFIBUS-DP (as Master, Slave and Multi-Slave), PROFIBUS-DPV1 (as Master) PROFIBUS-MC (as Master)
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Slave modules
With the dialog “Insert I/O device” it´s possible to insert the Beckhoff slave modules. If the Profibus Slave doesn´t exist in the list it´s possible to select Generic Profibus Box and search the profibus box in the gse file.
Each GSE file which was read by TwinCAT, can bee seen in the list ( with the name of the producer).
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Modular Structure of the Slaves modules
Beckhoff DP-Slave
General DP-Slave
xN
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Paint station (PRG)
Load example
contact
Graphical elements in LD
Cursor in KOP is used for inserting new elements
coil
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context menue
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Insert new elements
Identifier
The following elements can be inserted at the marked cursor positions 173
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Paint station (PRG)
Load example
Graphical elementes in FBD
Cursor in FBD is used for inserting new elements
Operator
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Context menue
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Insert new elements
List of the operators (AND, OR, GE, ADD, ..) implemented by the system.
Dependent by the the cursor position the following language elements can be inserted.
The program can be expand to the left and the right side.
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