1. S7- SCL Structured Control Language
SCL
STEP 7
CFC
Libraries
Overview
GRAPH
Common project - data basis
SIMATIC S7
Siemens AG 2000. All rights reserved.
Date:
6.10.00
Filename:
HiGraph
2. Areas of application
ProAgent
ProTool / ProTool lite
The high-level language for
programming the
S7-300,
S7-400,
and C7
WinCC
Modular PID
Fuzzy Control
Standard PID
DOCPRO
TeleService
S7-PLCSim
S7-PDiag
CFC
S7-HiGraph
IF data processing THEN
S7-SCL;
END_IF;
PRODAVE
S7-Graph
M7-ProC/C++
S7-SCL
Borland C/C++
LAD/STL/FBD
S7-300/400
STEP 7
M7-SYS
M7-300/400
SIMATIC S7
Siemens AG 2000. All rights reserved.
Date:
6.10.00
Filename:
3. What is SCL?
SCL (Structured Control Language)
Based on the language standard DIN EN-61131 Part 3 (int. IEC 1131-3)
Similar to the Pascal programming language
SCL Commands
.
.
IF New_value<>Old_value THEN
index :=(index mod max_values) + 1;
measurement_values[index] :=INT_TO_REAL(measurement);
END_IF;
.
.
SIMATIC S7
Siemens AG 2000. All rights reserved.
Date:
6.10.00
Filename:
4. Customer Benefits
Language is easy to learn
Shorter program development time, easier to read programs
Simple formulation of complex algorithms
Supports the block and data-type concepts of S7
System integration into S7 languages, such as LAD, FDB and STL
SIMATIC S7
Siemens AG 2000. All rights reserved.
Date:
6.10.00
Filename:
Notas do Editor
Contents Page
Areas of use2
What is S7 SCL ?3
Customer benefits4
Areas of applicationComplex mathematical functions, e.g. regulatorsData managementProcess optimisationRecipe managementStatistics, mathematicsQuality controli.e.Programs with a lot of branches or loops
Target systemsSIMATIC S7-300 and S7-400SIMATIC C7
DependenciesS7- SCL sits on top of STEP7 BasisS7- SCL is also required if project planning is done with the CFC for S7-300 or S7-400.
IntegrationS7- SCL is integrated seamlessly into the STEP7 architecture, which means that both the data basis and the operating philosophy are identical. Anyone who is already familiar with STEP7 and knows a high-level programming language can be working with SCL after a very short familiarisation period.
High level textual programming language
SCL (Structured Control Language) is a high level textual programming language for the automation systems S7-300/400 and C7. The programming effort for complex calculations, algorithms, data management and data organisation in control technology can be simplified with the aid of SCL.
Like PascalAs with Pascal, SCL offers all the advantages of a high level programming language. Besides a clear control structure and an extensive data concept, SCL also possesses other important concepts such as procedures and functions. This allows clear and easy to read programs can be developed.
DIN EN-61131-3The DIN EN-61131-3 (int. IEC 1131-3) standard standardises the programming language for programmable controllers. The basis for SCL is the part ST &quot;Structured Text&quot;. SCL is the Siemens label for this language, since there are specific deviations from ST, as is documented by the Compliance chapter of the standard.
A precise definition of the standards fulfilled can be found in the file NORM_TAB.WRI (German) or the file NORM_TBL.WRI (English) in the subdirectory you selected during SETUP (default setting: C:SIEMENSSTEP7 ).
LearnabilitySCL is easy to learn if you have had some experience in a high level programming language, because the repertoire of available language constructs in SCL is oriented towards high level programming languages.
Shorter Program development time
The fact that the language is easy to learn means, among other things, that the program design time is reduced, and that the programs are easier to read. This also allows the costs for service and maintenance of program sections to be reduced.
Complex Algorithms
With the help of the language construct functions that are available in SCL, particularly complex algorithms, such as those that arise in closed loop control tasks or other recipes, are simple and efficient to formulate.
Block Concept of S7
SCL particularly supports the block concept of STEP 7and therefore allows standard-compliant programming of all blocks(OB, FC, FB, DB, UDT) according to the norm DIN EN 61131-3 along with STL, LAD and FDB.
System integration into STL, LAD, FDB and CFC
Blocks that have been programmed with SCL can be combined with STL, LAD and FDB blocks. This means that blocks which have been programmed and tested in STL, LAD or FDB can be called up by SCL blocks. The reverse is also true, blocks written in SCL can also be called up by STL, LAD or FDB blocks.
Naturally, blocks written in SCL can also be used in CFC.