Summary Of Retentive Behavior; Retentive Behavior Of The Memory Objects - Siemens S7-1500 Function Manual

Memory areas and retentive memory

2.4 Summary of retentive behavior

2.4 Summary of retentive behavior
2.4.1

Retentive behavior of the memory objects

This section gives an overview of the retentive behavior of the memory objects of the CPUs.
In addition to the retentive memory areas described, there are other objects with retentive
characteristics, for example, the diagnostics buffer. These objects do not occupy any storage
space in the retentive memory.
The following table shows the retentive behavior of the memory objects in the case of the
following:
● STOP → STARTUP
● POWER ON → STARTUP
● POWER ON → STOP
● "Memory reset"
● "Reset to factory settings"
Table 2- 1 Retentive behavior of the memory objects
Memory object
Actual values of the data blocks, instance data
blocks
Bit memories, timers and counters
- configured as retentive
Bit memories, timers and counters
- configured as non-retentive
Retentive tags of technology objects
(e.g. calibration values of absolute encoders)
Diagnostic buffer entries
Operating hours counter
Clock time
Redundancy ID
3)
x = content is retained
– = object is initialized
For DBs with optimized access the retentive behavior is configurable for specific tags.
1)
Not for the CPUs of the redundant system S7-1500R/H
2)
Only for the CPUs of the redundant system S7-1500R/H
3)
30
STOP → STARTUP
POWER ON → STARTUP
POWER ON → STOP
Can be set in the properties of
the DB in STEP 7
x
-
x
2)
x
x
x
x
Memory
reset
-
1)
-
-
x
x
x
x
x
Structure and Use of the CPU Memory
Function Manual, 10/2018, A5E03461664-AC
Reset to factory set-
tings
-
-
-
-
-
-
-
-