BRONKHORST FlowDDE - SETTINGS

BRONKHORST®
Page12FlowDDE     9.17.067
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AtDeviceinformationinformationabouttheselectedchannelinthelistonthelefthandsideisshown.Nodeshows
thecurrentnodeaddressof theinstrument.Thenodeaddressof aninstrumentcanbechangedbypressingChange
andenteringthenewnodeaddress.Formulti‐channeldevices,e.g.
anRS232/FLOW‐BUSinterface,theprocessofthe
channelisshownatProcess.
ThecheckboxPollindicatesthatselectedparameters–thosemarkedPollintheparameterlist–fromthischannelare
polledbyFlowDDEwhenthecommunicationisopen.
Anycommentsabouttheinstrumentcanbeenteredin
theInfofield.ThesecommentsarestoredbetweenFlowDDE
sessionsaslongastheFLOW‐BUSconfigurationisnotchanged.
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Theconfigurationwindowallows basictestingofaselectedinstrument.TheMeasureispolledandaSetpointcanbe
writtenatOperationtest.
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4.3 SETTINGS
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TooptimizeFlowDDEforyourapplicationortocontrolresources, thebehaviourofFlowDDEcanbeconfigured.The
settingsaredividedintotwocategories:polltimeandsystemsettings.
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4.3.1 Polltime
ParametersofwhichthevaluemaychangefrequentlyarereadbyFlowDDEperiodically.
Those parameters are marked Poll in the parameter list. How often these parameters
arepolled,isdeterminedbythepolltime.Thelowerthepolltime,themoreoftenthe
parametersareread,butthehighertheCPU
loadbecomes.
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ThepolltimecanbechangedatServer>>Polltime.Thewindowattherighthandside
popsup.Itcontainsthreesettings:
 Polltime:thetimebetweentwopollrequests.
 Batch of channels: the number of channels that are polled at once.
The next poll time the next batch is
polled.ThispreventshighCPUloadsduetomanychannelsbeingpolled,butreducestheactualpolltimeper
channelasthetotalnumberofchannelsisdividedbythebatchofchannels.
 Real‐time poll time: the poll time for
the real time channels in case an RS232/FLOW‐BUS interface box is
usedwithreal‐timepollingenabled.Thisrequiresspecialconfiguration,usedbye.g.FlowPlot.
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4.3.2 Systemsettings
OthersettingsthanrelatedtothepolltimeareavailablebyServer>>Settings.
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Thebasicsettingsare:
 Retrynetwork access:numberoftimesa readorwrite
requestisretriedafterafailure.
 Poll parameters on initialization: after opening
communication all parameters of all devices are
 read,
sotheinitialDDEvalueisfilled.
 Suppress compatibility errors: older instrument don’t
havethelatestparameters.Readerrorsrelatedtonon‐
existingparametersaresuppressed.
 Hideadvancedparameters:hide advancedparameters
in parameters lists and FlowDDE windows. For normal
instrument operations, the hidden parameters are
not
needed. For maintenance or service, these parameters
maybe neededvisibleandthisoptioncan be disabled.
Althoughtheseparametersarehidden,theycanstillbe
reachedviaDDE.
 Trim CRLF from received DDE value: some Windows
applications send a carriage return and line feed with
each DDE
command. FlowDDE can remove them. For
binaryparameters,thiswillnothappen.