User Manual

Automation stations
Data storage
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16 Power restoration - COMA
Power restored. Operating state before power failure was COMA.
Actions (cold start response):
● Stop I/O scan
● Stop BACnet communication
● Stop XWP communication
D-MAP processing is stopped.
Summary
Every time the automation station restarts (Powerfail, Reset) a cold start is carried out.
The operating state is stored as a non-volatile variable.
The operating state is mapped as follows to the system status [SysSta] property of the device object:
Operating mode System status property [SysSta]
STOP (no D-MAP program loaded) DOWNLOAD_REQUIRED
STOP (D-MAP program loaded) NON_OPERATIONAL
RUN (D-MAP program loaded) OPERATIONAL
18.5 Data storage
The following memory types are used in the automation station:
● RAM: The content is lost during a cold start. Read and write access is possible any time without any
special action.
● Battery supported RAM: Operating hours and trend data are preserved during a cold start if the battery
is loaded.
● Flash memory: The content is retained during a cold start. Read access is possible at any time. Write
access is only possible via a special driver and with restrictions (access time, sequential only).
The data and code of a D-MAP program are saved in the flash memory during the download process. A
copy of the data is always stored in the RAM so that the D-MAP program can access data efficiently for
processing purposes. This means, that all changes to the program data must be updated both in the RAM
and in the flash memory.
The following figure shows the various sequences: