Operating instructions

Functions
9.6 SRAM buffer memory
SIMATIC IPC627C
62 Operating Instructions, 11/2010, A5E02669068-02
Function of the LED H1, H2
During the BIOS startup, the two LEDs light up in three colors (red, yellow and green) to test
their operation. The two LEDs switch off when the startup is completed without errors.
Applications can trigger the two LEDs if required.
Note
You will find the programming interface and sample programs on the DVD
"Documentation & Drivers" in the folder "Drivers\DiagBase\program
files\Siemens\DiagnosticManagement".
9.6 SRAM buffer memory
In order for applications to store data following a power failure, the motherboard features
battery-buffered SRAM. If the supply voltage fails for more than 20 ms for the AC power
supply or more than 5 ms for the DC power supply, then you will be informed about this
situation by the NAU signal.
At least 10 ms is available to copy the data to the buffered RAM. During this time, 128 Kb
can be saved with a full load and even more with a smaller configuration, in other words, a
lesser load. A maximum 2 MB memory window is displayed via a PCI address register. The
base address is initialized by the BIOS.
A corresponding function is implemented there for using the SRAM under WinAC RTX.
NOTICE
If replacement of the battery takes longer than 30 seconds, the data saved in the CMOS
RAM and in the buffered SRAM is lost.
Note
The buffer memory SRAM is available only with devices with PROFIBUS or PROFINET
interfaces.
9.7 Battery monitoring
The installed buffer battery has a service life of at least 5 years. The status is checked by a
two-stage battery monitoring function and is displayed and evaluated by the DiagBase or
DiagMonitor software
When the first warning level is reached, the remaining service life of the battery for buffering
CMOS data amounts to at least 1 month.