01.99 11 Data Backup/CPU Replacement
11.1.2 General notes on data backup
11.1.2 General notes on data backup
Loss of data occurs in case of
• hardware defect on the module
• hard disk defect
• backup battery failure (loss of SRAM data)
• withdrawal of modules CSB, NC CPU, MMC CPU
• EMC influence
Data range
Hardware overview
NCK
DRAM not buffered
NCK data
SRAM buffered
NCK data
PLC
SRAM buffered
PLC user program
memory
PLC memory
PLC system data
Drive 611D
DRAM not buffered
Drive machine data
DRAM not buffered
MMC
SRAM
clock
TEA2
PLC machine data
Hard disk
MMC data
WOP data
NCK data
PLC user program
611D configuration
and MD
Boot file 611D
Note:
The CSB battery is used for SRAM data buffering.
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 11–3
SINUMERIK 840C (IA)