Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 78)

L-force | PLC Designer
What is What in PLC Designer
76 DMS 3.2 EN 02/2011 TD29

4.3.8 Simulation
During the simulation the created PLC program is not processed in the PLC, but rather
in the calculator on which PLC Designer is running. All online functions are available.
That allows you to test the logical correctness of your program without PLC hardware.
Note!
POUs of external libraries do not run in simulation mode.
4.3.9 Log
The log chronologically records user actions, internal processes, state changes and
exceptions during Online mode processing. It is used for monitoring and for error
tracing (see Online Functions).
4.4 The Standard...
The standard IEC 61131-3 is an international standard for programming languages of
Programmable Logic Controllers.
The programming languages offered in PLC Designer conform to the requirements of
the standard.
According to this standard, a program consists of the following elements:
• Structures (see Data Types)
• POUs
• Global Variables
The general language elements are described in the sections Identifier, Addresses,
Types, Comments, and Constants.
The processing of a PLC Designer program starts with the special POU PLC_PRG. The
POU PLC_PRG can call other POUs.