SBC PCD2.M5 Series - Page 52

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
3-39
3
Storingatext/DBontheashcardwithSYSWRK3000
Storingatext/DBontheonboardashwithSYSWRK3100
Instruction:
SYSWR K 3x00
1)
K number ;addressofthetexts/DBsas
;Kconstantorinaregister,
;existingtext/DB
;addressesintherange>=4000
;maybeused
1)Alternatively,thevalue3x00canbepassedinaregister.
Battery status after execution:
low: thetext/DBhasbeensaved,andtheashcardisready
for new SYSWR instructions
high: thelastinstructionwasnotprocessedtocompletion;
before further SYSWR K 3x0x instructions, a SYSRD
K 3x0x must be executed to check the readiness of the
ashcard
When using the instruction SYSWR K 3x00, note the following:
● Afteranychangeofmemoryconguration,a“backupuserprogramtoash”must
berun,toensurethatthe“backupDBtoash”willwork(partitioningtheash).
● Theashcardcanbewrittentoamaximumof100,000times,soitisnotpermis-
sible to invoke the instruction in a cyclical manner or at short intervals.
● It is strongly recommended to execute a SYSRD K 3x00 before this instruction, to
testwhethertheashcardisavailableandready.
● The processing time for the instruction may be up to 100 ms. At that point, there
isnoguaranteethatallofthetext/DBhasbeenwritten(theprocesswillcontinue
inbackground).Forthisreason,theinstructionmustnotbeinvokedinXOB0
(XOBforapowerfailure)orduringtime-criticalprocesses.
● Iferrorsoccurduringprocessing,XOB13willbecalledwhereitispresent,orthe
error LED will be set
● When starting the PCD after a loss of RAM memory, the state of the texts/DBs
after the last download is restored, even where the SYSWR K 3x00 instruction
has been used to store newer versions.
● Within the maximum number of write cycles, a text/DB can be stored any number
oftimes,withouttheashcardbecomingover-full.