Siemens SIMATIC ET 200pro Operating Instructions Manual page 107

Test and service functions
10.1 Test functions
Testing with program status
The program status allows you to monitor the execution of the program. You can hereby
display the values of operands and the results of logic operations (RLO). This allows you to
detect and fix logical errors in your program.
Note
Restrictions with the "Program status" function
Monitoring 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 numbers of loops run through.
Testing with program status
A test with the "Program status" function can cause serious damage to property or injury to
persons if there are functional disturbances or program errors.
Make sure that you take appropriate measures to exclude the risk of dangerous states
occurring before running a test with the "Program status" function.
Testing with breakpoints
With this test option, you set breakpoints in the program code, establish an online connection
and enable the breakpoints on the CPU. When testing with breakpoints, you run a program
from breakpoint to breakpoint.
Requirements:
● You can set breakpoints in the programming languages SCL or STL
Testing with breakpoints offers the following advantages:
● Narrowing down logic errors step-by-step
● Simple and rapid analysis of complex programs before actual commissioning
● Acquisition of actual values within individual loop passes
● Utilization of breakpoints for program validation also possible in SCL networks with LAD /
FBD possible
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WARNING
CPU 1516pro-2 PN (6ES7516-2PN00-0AB0)
Operating Instructions, 11/2019, A5E35873416-AC