Siemens SIMATIC ET 200SP System Manual page 260

Testing with program status
The program status allows you to monitor the execution of the program. You can display the
values of operands and the results of logic operations (RLO) allowing you to recognize and
fix logical errors in your program.
Note
Restrictions for the "Program status" function
The monitoring of loops can significantly increase the cycle time. The increase in cycle time
depends on the following factors:
• The number of tags to be monitored
• The actual number of loops run through
Testing with program status
A test with the "Program status" function can produce serious property damage and
personal injury in the event of malfunctions or program errors.
Make sure that you take appropriate measures to exclude the risk of hazardous conditions
occurring before running a test with the "Program status" function.
Testing with breakpoints
With this test option, you set breakpoints in your program, establish an online connection,
and enable the breakpoints on the CPU. You then execute a program from one breakpoint to
another.
Requirements:
● Setting breakpoints is possible in the programming language SCL or STL.
Testing with breakpoints provides you with the following advantages:
● Localization of logic errors step by step
● Simple and quick analysis of complex programs prior to actual commissioning
● Recording of current values within individual executed loops
● Use of breakpoints for program validation also possible in SCL/STL networks within
LAD/FBD blocks
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ
WARNING
Test and service functions
13.1 Test functions
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