Operating the device and device functions
5.6 Extended device functions
SIMATIC IPC477D, IPC477D PRO
Operating Instructions, 11/2016, A5E31347228-AF
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5.6.1.4
Battery monitoring
The installed backup battery has a limited service life, see section "Replacing back-up
battery (devices with 15", 19" or 22" display) (Page 155)". 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.
5.6.2
Enhanced Write Filter
Purpose and function
The EWF (Enhanced Write Filter) is a function that is only available for Windows Embedded
operating systems. It provides write protection that can be configured by the user.
You can use the Enhanced Write Filter to boot Windows Embedded Standard from read-only
media, for example, CFast card, or provide individual partitions with write protection.
EWF can be used to minimize write access to CFast cards. This is important because the
write cycles on CFast cards are limited due to technical reasons. We therefore recommend
using EWF if you work with CFast cards.
EWF is indispensable when HORM or compressed NTFS is used.
NOTICE
Activate only one write filter per partition - otherwise you risk data loss
EWF and FBWF are preinstalled in the SIMATIC IPC images.
Ensure that only one write filter is enabled on a partition, otherwise you risk data loss.
Note
The Enhanced Write Filter is deactivated in the Windows Embedded Standard default state.
After the operating system and programs have been installed, you should back up your data
and then enable the EWF.