Siemens S7-1500 Function Manual page 71

SIMATIC memory card
4.4 Service life of the SIMATIC memory card
Guaranteed data retention time
If you do not use your SIMATIC memory card for an extended period of time, there is the risk
that data contained on the memory card may no longer be readable after a certain amount of
time.
The guaranteed data retention time of a SIMATIC memory card is 10 years on delivery and
with proper storage. With a number of ≤ 10% of the maximum write/delete operations, the
data stored on the card has a retention time of 10 years.
Please note that increasing numbers of write/delete operations to the card reduces its data
retention time. If 90% of the maximum write/delete operations is reached, the guaranteed
data retention time is reduced to 1 year. If 100% of the maximum write/delete operations is
reached, the retention time of the saved data can no longer be guaranteed.
Determining the current usage level of a SIMATIC memory card in STEP 7
When you activate the "Aging of the SIMATIC memory card" option, you enter a threshold
value as a percentage in the text box below. As soon as the service life of the SIMATIC
memory card has reached the specified threshold value (e.g.: 80%), the CPU outputs a
diagnostics alarm.
Figure 4-3 Enabled option "Aging of the SIMATIC memory card"
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Structure and Use of the CPU Memory
Function Manual, 10/2018, A5E03461664-AC