Date:06.12.2015 File:PRO1_11E.1 SIMATIC S7 Siemens AG 1999. All rights reserved. Information and Training Center Knowledge for Automation Functions and.

Date: 21.04.23File: PRO1_11E.1

SIMATIC S7Siemens AG 1999. All rights reserved.

Information and Training CenterKnowledge for Automation

Functions and Function Blocks




Introduction

Temporary Variables

• are deleted after the associated block is executed

• temporary storage in L stack

• useable in OBs / FCs / FBs

Static Variables

• are retained even after the block is executed

• permanent storage in DBs

• can only be used in FBs

Local Variables / Data

(only valid in one block)

Global Variables / Data

(valid in the entire program)

• PII / PIQ

• I/ O

• M / T / C

• DB areas

symbolicabsolute

Access




Temporary Variables




Execution

Local Data Stack Size

For S7-300:

L stack sizePriority class

256 bytes1

27

Entire size: 1.5 Kbyte

(CPU 313..316)

Entire size: 1.5 Kbyte

(CPU 313..316)

Startup (one-time execution)

Cyclic execution

256 bytes

256 bytes

256 bytes12

3

2Time-controlledexecution

Time-of-Day Interrupt

Time-Delay Interrupt

Cyclic Interrupt

Error handling in scan cycle

256 bytes16

28

26256 bytes

Event-driven execution

Hardware Interrupt

Error handling in startup




Byte Requirement of a Block in the Local Data Stack

rechts




25

6 B

yte

s

Event

Occupation in the L stack

1

OB1

OB 1

1

Operatingsystem

Total Occupation in the Local Data Stack

FC 2

with temp.variables

OB1

FC2

FC1

3

3

OB1

FC1

4

4

OB1

FC1

6

6

FC 3

with temp.variables

OB1

FC3

FC1

5

5

FC 1

with temp.variables

2

OB1

FC1

2

7

OB1

7




Exercise: Use of Temporary Variables

Replace by the temporary variable

"Packages"




Example of a Message Display Indicating a Problem in the Process

Disturbance

LED

Acknowledge

Report Memory

Edge Mem. Bit

Disturb. Input

Acknowl.

Flash Freq.

Disturb. Input

Display

RS

&

=

>=1&QS

RP

Report Memory

Report Memory

Solution Suggestion

Task




Disturb.input

Report memory

Acknowledge

Edge mem.bit

Display

Flash freq.

FC 20

Call

Parameter-Assignable Blocks

A I 1.2

R M 40.0

A I 1.3

FP M 40.1

S M 40.0

A M 40.0

A M 10.3

O

ANM 40.0

A I 1.3

= Q 8.3

Non-parameter- assignable block

Formal parameters

M 40.0

M 40.1I 1.3

I 1.2 A 8.3

M 10.3

Actual parameters

A #Acknowledge

R #Report Memory

U #Disturb. input

FP #Edge mem. bit

S #Report memory

A #Report memory

A #Flashing freq.

O

AN #Reportmemory

A #Disturb. input

= #Display

Parameter-assignable block

Program

Date: 21.04.23File: PRO1_11E.10



Declaration of the Formal Parameters

Use Graphic Display

Read only To the left of the block

Write only To the right of the block

Type of parameter

Input parameter

Output parameter

In/out parameter

Declaration

in

out

In_out Read / write To the left of the block

Formal parameters

Declaration table of the FC 20 block

Date: 21.04.23File: PRO1_11E.11



Editing a Parameter-assignable Block

Here was, e.g., with a non-parameter-assignable FC:

• with absolute addressing: I1.3

• with symbolic addressing: “End_left"

Date: 21.04.23File: PRO1_11E.12



Calling a Parameter-assignable Block

Network 3: First Call

Network 4: Second Call

Disturb.input

Acknowledge

Flash freq.

Report memory

Edge mem. bit

Display

M40.1

“Position error"

ENO

EN

“End left"

....

“Acknow.button"

M10.3

M40.0

FC20

Disturb.input

Acknowledge

Flash freq.

Report memory

Edge mem. bit

Display

M40.3

Q9.4

ENO

EN

“End right"

A8.1

“Acknow.button"

M10.3

M40.2

FC20

symbolic

absolute

Addressing

Symbols Local Symbols --> Formal parameters

Symbol-table

Global Symbols

Date: 21.04.23File: PRO1_11E.13



LAD/FBD STL

Using the EN/ENO Parameters with Block Calls

CALL FC 1 NOP 0

Example

?? . ?

FC 1

EN ENO

FC 2

EN ENO

FC 3

EN ENO =

FC 1

EN ENO?? . ?Unconditional call

A I 0.1 JNB _001

CALL FC 1 _001: A BR

= Q 9.0

FC 1EN ENOI 0.1 =

Q 9.0

Conditional call

Date: 21.04.23File: PRO1_11E.14



Declaration table of the FC 20 block

Exercise: Creating a Parameter-assignable FC Block

Non-parameter-assignable block

Parameter-assign-able FC 20 block

A I 1.2R M 40.0A I 1.3FP M 40.1S M 40.0A M 40.0A M 10.3OAN M 40.0A I 1.3= Q

9.3(Q5.3)

A #AcknowledgeR #Report memoryA #Disturb. ...::::::::

2.

1.

Date: 21.04.23File: PRO1_11E.15



Exercise: Calling a Parameter-assignable FC Block

Disturb. input

Report memory

Acknowledge

Edge mem. bitDisplay

Flash freq.Parameter-assignment of FC20 in the 1st. call

M 40.0

M 40.1I 1.3

I 1.2 Q 9.3 (Q 5.3)

M 10.3

FC 20

Disturb. input

Report memory

Acknowledge

Edge mem. bitDisplay

Flash freq.

M 40.2

M 40.3I 1.4

I 1.2 Q 9.4 (Q 5.4)

M 10.3

FC 20

Parameter-assignment of FC20 in the 2nd. call

Date: 21.04.23File: PRO1_11E.16



Function Blocks (FBs)

FB 2

EN

Disturb. input

Acknowledge Display

Flash freq. ENO

DB 2

OB 1

Declaration table of the function block

Date: 21.04.23File: PRO1_11E.17



Function Block for Message Display

Declaration table of the functionblock

Instancedata block

Date: 21.04.23File: PRO1_11E.18



Generating Instance Data Blocks

1. Generate instance DB with FB call 2. Create new instance DB

Date: 21.04.23File: PRO1_11E.19



The Multiple Instance Model

DB10

The Instance Model

FB20

OB 1

Call FB20, DB10Disturb._Input:=Acknowledge:=Flash_Freq:=Display:=

DB11

FB20


DB12

FB20


The Multiple Instance Model

FB 100

DB100

Call FB100, DB100

OB 1

stat Dist_1 FB20

stat Dist_2 FB20

Parameters andstatic variablesof the 2nd. call of FB20

Call Dist_2Disturb._Input:=Acknowledge:=Flash_Freq:=Display:=

Parameters andstatic variablesof the 1st. call of FB20

Call Dist_1Disturb._Input:=Acknowledge:=Flash_Freq:=Display:=

Date: 21.04.23File: PRO1_11E.20



Inserting/Deleting Block Parameters Later On

Save

Date: 21.04.23File: PRO1_11E.21



Corrections when Calling Modified Blocks

When the calling block is opened:

Once with the right

Date: 21.04.23File: PRO1_11E.22



Exercise: Editing a Function Block

Declaration table of the FB 20 block1.

Program section of FB 20A #AcknowledgeR #Report memoryA #Disturb. ...::

2.

Date: 21.04.23File: PRO1_11E.23



Exercise: Calling a Function Block and Testing It

(Q 5.3)

(Q 5.3)

Date: 21.04.23File: PRO1_11E.24



Converting an FC to an FB using a Source Program (1)

Date: 21.04.23File: PRO1_11E.25



Converting an FC Block to an FB using a Source Program (2)

::

::

Date: 21.04.23File: PRO1_11E.26



Exercise: Recognizing Types of Variables

Absolute Symbolic Temporary Static Parameter

L #Number_1

T #Max_value

T MW 40

Statement

L #Number_2

L #Intermediate_resultL “Number_1"

T #Number_2

Global Local

Date: 21.04.23File: PRO1_11E.27



Summary: Block Calls

• CALL FC1

• UC FC1

• CC FC1

STL

LAD

FBDFC1

EN

ENO

FC1EN ENO

FC1

( CALL )

FB

W/o param., w/o inst. DB

• UC FB1

• CC FB1

FB1EN

ENO

FB1EN ENO

CALL

With parameters

• CALL FC2 Par1: ... Par2: ... Par3: ...

FC2EN ENO

Par3

Par1

Par2

FC2EN

ENO

Par1

Par2

Par3

With param., with inst.DB

• CALL FB2, DB3 Par1: ... Par2: ... Par3: ...

FB2EN ENO

Par3

Par1

Par2

DB3

FB2EN

ENO

Par3

Par1

Par2

DB3

Without parametersLan-guage

FC

FC1

Date:06.12.2015 File:PRO1_11E.1 SIMATIC S7 Siemens AG 1999. All rights reserved. Information and Training Center Knowledge for Automation Functions and.

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