Lenze c300 - Manual (Page 64)

Lenze · Controller | Parameter setting & programming · Reference Manual · DMS 1.5 EN · 04/2014 · TD17
64
7 Programming with the »PLC Designer«
7.5 Creating remanent variables (retain/persistent)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
7.5 Creating remanent variables (retain/persistent)
Retain variables ...
• are variables of the PLC which are automatically saved by the controller in the case of a voltage
failure.
• are variables which are necessary to restart the production process.
The values of a drive system which cannot be read out from the machine due to the lack of a sensor
system should be persistent. These values should also be persistent if the corresponding value only
changes through the influence of the PLC.
Examples
Temperature: Changes, requires a sensor system
Position: Selection preferably via absolute value encoder
Number of parts within buffer inventory: Reasonable for RETAIN.
Persistent variables ...
can be created in the device tree in the »PLC Designer«:
Right-click ApplicationNew object Persistent variables.
VAR RETAIN
remvar1: INT; (* 1st remanent variable*)
END_VAR
VAR_GLOBAL PERSISTENT RETAIN
uiPerRetain : ARRAY[0..1000] OF UNIT; (* declaration of the persistent variable*)
END_VAR

»PLC Designer« Online help
Further information on remanent variables can be found in the "remanent variables"
section.
Further information on the export of symbol files can be found in the "Symbol
configuration editor" section.