Siemens SIMATIC S5-115U, User Manual

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S5-115U Manual PLC System Start-Up and Program Test
4.3 Testing the Program
The following describes the steps for starting the control program in the S5-115U. This is followed
by the description of the test functions with which you can locate logical errors in program
processing.
4.3.1 Starting the Program
Starting point: The PS 951 power supply module is switched off, the CPU mode selector is at
STOP, the control program is stored on the E(E)PROM submodule.
Insert the memory submodule in the receptacle of the CPU
Switch on the power supply module
The green LEDs of the PS 951 light up (otherwise: power supply module (PS 951) defective)
(if desired:) Overall Reset of CPU
After switching on the power supply module or after Overall Reset (mode selector at STOP), the
STOP LED and the BASP LED light up.
If the STOP LED
flickers, the CPU is defective; if the STOP LED flashes, there is a fault in the
memory submodule (see Chapter 5).
Online functions with the programmer over the serial interface are possible when the CPU is in
the STOP state.
Set the mode selector from STOP to RUN
Both operating mode LEDs light up during the entire restart.
After the restart OB has been processed, the RUN LED lights up (cyclic program scanning).
In the event of a fault, the CPU remains in the STOP state, i.e. the STOP LED lights up. Analysis of
the cause of the interrupt is described in Chapter 5.
If the control program does not work properly, you can debug the program with the "STATUS",
"STATUS VAR" and "FORCE VAR" test functions.
Note
Test functions increase the scan time of the running control program!
EWA 4NEB 811 6130-02b
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