9Memorymode
Page 3
Sothattheacquisitionofaperiodic signalisconvenient,youshouldselectasamplingperiodthatis
compatiblewiththefrequencyofthe signalsattheinputterminalsoftherecorder.
A10-dot-per-signal-periodaccuracyisminimumforaconvenientplotting

9.3.Internalmemory,blocks

Youcandividetheavailablememoryoftherecorderintoblocksthatwillbefilledoneafterthe
otherateachacquisition.
TheamountofdataofacquisitionisworthN/(B*V)
N=totalmemory
B=numberofblocks
V=numberofchannelstocollect
Example:memory:32Mbytes,16blocksand3channels"ON";youwillhave
N=32,554,432/(16*3)=699,050bytes/channel
Anynewacquisitionwillbeplacedautomaticallyintothefirstfreeblockavailable(inincreasing
sense).
Wheneveryblocksarefull,anewacquisitionwillshiftthepreviousblockNintotheblockN-1;the
1st blockwillbelost.
Thenewacquisitionwillthentaketheplaceofthelastblock.

9.4.Triggeringposition

Theacquisitionintoamemoryblockisbasedonthe systemofthe rotarymemory :
-thememorystartsfillingfromthestartcondition
-thememorykeepsonfillingaslongasthestopconditionisnotvalid;ifthememoryis
full,thefillingrestartsfromthebeginningofthememoryzone(block)
Thus,thememoryblockalwayscontainstheNlastsamples.
Theusercanchoosethemomentwhenthesamplesinthememorywillbefrozen:todoso,hewill
defineadelaybetweenthetriggeringmomentandthebeginningoftheeffectivetransferinto
memory.
Thisdelaycanbepositiveornegative. Thesamplesinmemorycanthusbeeitherbeforeorafteror
onboth sidesofthetriggeringmoment.
Wecanalsonotinhibitthetriggerduringthepretriggerphase:thisallowtotestthetrigger
conditionduringthepretriggerphaseandmakethetriggerfunctionevenifthepretriggertimeisn t
passed.
MEMORY
TRIGGERING
MEMORYSTART
-50 %
MEMORY
TRIGGERING
MEMORYSTART
+50 %