Siemens Simatic S7-200 System Manual page 61

Viewing a Program in Ladder Logic or Statement List
You can view a program in either ladder or STL by selecting the menu command View
or View Ladder, as shown in Figure 3-24.
When you change the view from STL to ladder and back again to STL, you may notice
changes in the presentation of the STL program, such as:
Instructions and addresses are changed from lower case to upper case.
Spaces between instructions and addresses are replaced with tabs.
You can accomplish the same formatting of the STL instructions by selecting the menu
command CPU
Note
Certain combinations of statement list instructions cannot be converted successfully to
ladder view. In that case, the message "Illegal Network" marks the section of code that
cannot be represented in ladder.
STEP 7-Micro/WIN - c:\microwin\project1.prj
Project Edit View CPU Debug Tools Setup Window Help
Ladder Editor - untitled.ob1
Contacts
Network 1
"Start1"
Figure 3-24
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
Installing and Using the STEP 7-Micro/WIN Software
Compile while the STL Editor is active.
View
STL
Ladder
Data Block
Symbol Table
F2 Normally Open
Status Chart
Cross Reference
Start/stop switch
Element Usage
"E-Stop1" Q0.0
Symbolic Addressing Ctrl+Y
Toolbar
Status Bar
Instruction Toolbar
Zoom...
Changing the Program View from Ladder to Statement List
F3
F4 F5 F6 F7 F8
STL STL Editor - untitled.ob1
NETWORK 1 //Start/stop switch
LD "Start1"
AN "E-Stop1"
= Q0.0
NETWORK 2 //End
MEND
STL
F10
3-31