Commissioning the device and device functions
4.3 Advanced device functions
SIMATIC IPC277E
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Operating Instructions, 11/2019, A5E35783335-AE
4.3.1.4
Battery monitoring
The installed backup battery has a limited service life, see section "Replacing the backup
battery (Page 80)". A two-tier battery monitoring checks the status of the backup battery. The
SIMATIC DiagBase and SIMATIC DiagMonitor diagnostic software determines the status of
the backup battery.
When the first warning level is reached, the battery for buffering CMOS data still has a
remaining service life of at least one month.
4.3.2
Buffer memory NVRAM
The motherboard is equipped with an NVRAM that applications can use to back up data in
the event of a power failure. Failure of the supply voltage for a duration longer than 5 ms is
indicated by the DC FAIL signal.
At least enough time is provided for copying data to the NVRAM so that 128 KB can be
backed up with the full configuration.
A memory window with a maximum size of 512 KB can be displayed by means of PCI
address register. The base address is initialized via the BIOS (see section "Input/output
address areas (Page 122)").
A corresponding function is implemented there for using the NVRAM with a soft PLC.
