Siemens S7-1500 Function Manual page 28

Tags of a global data block
In a global data block, you can define either individual tags from a block or all of its tags
collectively as retentive, depending on the setting for the "Optimized block access" attribute:
● "Optimized block access" activated: In the declaration table of the data block, you can
define individual tags as retentive.
Figure 2-5
● "Optimized block access" not activated: In the declaration table of the data block, you can
only define the retentivity of all tags collectively.
Figure 2-6
You can find additional information on optimized and non-optimized data blocks in the
Programming guideline for S7-1200/S7-1500
(https://support.industry.siemens.com/cs/de/de/view/90885040/en).
Tags of an instance data block of a function block
You can define the tags of the instance data block of a function block as retentive in STEP 7.
Depending on the setting for the "Optimized block access" attribute, you can define
retentivity either for individual tags from a block or for all of its tags collectively:
● "Optimized block access" activated: In the interface of the function block, you can define
individual tags as retentive.
● "Optimized block access" not activated: In the instance data block, you can only define
the retentivity of all tags collectively.
Structure and Use of the CPU Memory
Function Manual, 10/2018, A5E03461664-AC
Retentivity setting "Optimized block access" activated
Retentivity setting "Optimized block access" not activated
Memory areas and retentive memory
2.3 Retentive memory areas
27