Program Processing With Cpu 102 - Siemens SIMATIC S5-100U System Manual

S5-100U
7.4.1

Program Processing with CPU 102

You can process the program in the following two modes:
• Normal mode
• Test mode
Program processing is faster in the normal mode, but you can not use the STATUS test function.
Transferring from one mode to the other is called a mode change.
Test Mode:
Scanning the STEP 5 program
Normal Mode:
The control program you have written in STEP 5 is not processed directly. What is processed is a
translated or runtime-optimized form of the program generated by the programmable controller.
Cycle trigger
Control
program
in STEP 5
Transfer
data
Test mode
EWA 4NEB 812 6120-02b
Assemble
(compile)
Figure 7-9. Program Scanning with CPU 102
Introduction to STEP 5
Cycle trigger
Runtime-
optimized
program
Transfer
data
Normal mode
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