Technical data

Memory areas and retentive memory
2.1 CPU memory areas
Structure and Use of the CPU Memory
Function Manual, 01/2013, A5E03461664-01
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Information on memory areas in STEP 7
In STEP 7 you can view the offline and online information about the memory areas of your
S7-1500 CPU.
Offline: When you are creating or modifying a program, you can determine whether it is too
large for a specific CPU. You can find this information under "Program information" in the
project tree, for example. On the Resources tab, you can find information about the total size
of the memory areas, and the storage space that has already been allocated. In this location
you can also find information about the assigned inputs and outputs. With a S7-1500 CPU,
you can select the total size of the load memory in a drop-down list.
The following figure shows the drop-down list for selecting the size of the load memory:
Figure 2-2 Drop-down list for the load memory
Online: While you are online, you can check the memory utilization of your CPU in STEP 7.
The online function "Memory" can be found in Online & Diagnostics under "Diagnostics >
Memory".
The image below shows CPU memory utilization in the online function "Memory":
Figure 2-3 "Memory" online function
You can find additional information on your CPU's memory in the following locations in
STEP 7:
● In Program information, on the Assignment list and Call structure tabs
● PLC tag table