Siemens SIMATIC S7-200 - Displaying the Status of a Program in Ladder Logic; Displaying the Status of the Program in Function Block Diagram

Basic Concepts for Programming an S7-200 CPU
4-33
S7-200 Programmable Controller System Manual
A5E00066097-02
SIMATIC LAD
Name Var Type Data Type Comment
I0.0
Network 1
Start
Stop
BOOL
BOOL
TEMP
TEMP
LAD Program status (end of scan)
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OUT
ADD_I
EN
IN1
IN2
OUT+777=VW0
+23=VW2
ENO
+800=VW4
MAIN SBR_0 INT_0
Figure 4-17 Displaying the Status of a Program in Ladder Logic
Displaying the Status of the Program in Function Block Diagram
You can monitor the status of the FBD program by using STEP 7-Micro/WIN 32.
STEP 7-Micro/WIN 32 must be displaying FBD. FBD status displays the status of
all instruction operand values. All status is based upon the values of operands that
were read at the end of a PLC scan cycle. STEP 7-Micro/WIN 32 acquires the
values for the status display across multiple PLC scan cycles and then updates the
FBD status screen display. Consequently, the FBD status display does not reflect
the actual status of each FBD element at the time of execution.