Siemens Simatic S5-101U - Intercompatibility between LAD, CSF and STL

3.5
Intercompatibility between LAD, CSF and STL
General
Each of the methods of representa-
tion in the STEP
5 programming
languages has specific properties
and limitations.
Consequently, a program block written
in STL cannot simply be displayed as
an LAD or CSF and the graphic methods
of representation, LAD and
CSFy may
not always be fully compatible.
In other words, one form cannot al-
ways be translated back into the
other form.
If the program has been entered as
Fig.
7: Range and limitations of the
an LAD or CSF,
it can always be trans- methods of representation in the
lated back into STL form. STEP
5 programming language
Input Output
The aim of this section is to establish
a number of rules, which,
if adhered to,
will ensure complete compatibility be-
tween the three methods of representation.
These rules are classified as follows:
- Rules for compatibility between the
graphic methods of representation
(LAD and CSF)
.
If these rules are followed, input is
possible in one graphic form and display
in the others.
Fig.
8: Graphic input
I nput Output
- Rules for compatibility between the
statement list and the graphic methods
of representat ion.
If these rules are observed, it is
possible to enter a program in any
if
the three methods of representation,
graphic or not, and to have
it dis-
played in the other two forms.
Fig.
9:
Input
in the form of
a statement list