Siemens SIMOTION Function Manual page 106

Changing the active configuration or the active kernel
6.5 Retaining retentive data in the event of a configuration change
Measures for retaining retentive unit variables
Proceed as follows to ensure the values of retentive unit variables are retained (not initialized)
during a configuration change:
1. Declare the retentive unit variables in a separate unit with the same identifier and the same
2. Ensure that an identical data structure is used in all configurations within this unit -
3. Use several declaration blocks in the unit, if necessary.
The retentive unit variables thus receive the same version code in all configurations.
If the retentive unit variables in the most recently activated configuration and the configuration
to be activated have the same version code, they are not initialized.
Note
When activating a configuration using an initial configuration, please also note the restrictions
for the initial configuration given in Selecting and activating a configuration using an initial
configuration (Page 99) (in the Notice information).
Note
If you do not observe the above procedure, the retentive unit variables will be initialized when
a different configuration is activated.
Also ensure the following setting is made for the download: The initialization of retentive
variables must be disabled (Options > Settings menu, Download tab).
Alternatively, unit variables even with functions _exportUnitDataSet and _importUnitDataSet
can be exported, saved and imported again.
Measures for retaining the retentive system variables of technology objects
Proceed as follows to ensure the retentive system variables of technology objects are retained
(not initialized) during a configuration change.
Configure the SIMOTION devices and the technology objects in the following manner in all
configurations:
1. Set the system variable of the SIMOTION device
2. Assign identical identifiers and object addresses for the same technology objects.
This prevents the retentive system variables of a technology object from being initialized when
the following conditions are met in the last configuration activated and the configuration to be
activated:
1. Identifier and object address of the technology object are identical.
2. The structure of the retentive system variables of the technology object is the same.
106
object address in all configurations.
particularly because of HMI device access.
_configurationManagement.preserveToRetainData := YES in offline.
Basic Functions for Modular Machines
Function Manual, 04/2014