SBC PCD2.M5 Series - Backup;Restore of RAM Texts;Dbs at Run-Time

Hardware Manual for the PCD2.M5 Series│Document 26/856; Version EN 12│2014-07-24
Saia-Burgess Controls AG
Memory space on the PCD
PCD2.M5_ Classic CPUs and expansion housings
3-38
3
3.12.5 Backup/restore of RAM texts/DBs at run-time
Asdescribedabove,theapplicationcanbecopiedtotheashcardafter
downloading. In order to store process data gathered during operation, there is a
facilitytocopytextsorDBsfromextensionmemory(address≥4000)totheash
card,orconversely,tocopythelaststatewrittentotheashcardbackinthetext/DB
in extension memory.
ThememoryspacerequiredtobackuptheDBs(extensionmemorybackup)mustbe
conguredinthe"Memory"tabinhardwaresettings.
Memory tab
On the Memory tab, the Extension Memory Backup Size can be set. This memory
sizerepresentsthememoryspaceforthe"Copyprogramtoash"function.On
the left-hand side, the currently available memory space for the user program is
displayed.
If the "extension memory backup size" is increased, the "user program backup size"
willbeautomaticallyreduced(bytwicethecongured"extensionmemorybackup
size")
Forstoringtexts/DBsontheashcard,restoring,deletingandrunningdiagnostics,
therearefourSYSRD/SYSWRinstructionsprovided,asdescribedindetailbelow;
these can be invoked at a suitable place in the user program. These instructions
mustbeusedwithgreatcare,topreventanydamagetotheunitortheashcard.