BRONKHORST FlowDDE - PARAMETER INFORMATION; DDE String

BRONKHORST®
Page8FlowDDE     9.17.067
3 PARAMETERINFORMATION
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FLOW‐BUS is used for parameter value exchange between instruments and operation modules (keyboard or PC‐
interface). Parameter information consists of several properties for behaviour within the FLOW‐BUS system. In the
‘parameterproperties’tableyouwillfindalistofparametersandtheirproperties.Inthe‘parametervalues’table,
the
valuesaredescribedmoredetailed.Thislistconsistsmostlyofparametersformodesettings.
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Propertydescriptioninparameterpropertiestable
Item Description
Parameter(DDE) Uniqueparameternumber(alsousedforDDE‐communication:P(x)).
Name Nameoftheparameter,usedforparameteridentification.
Process ProcesswhereparameterisusedonFLOW‐BUSmodule, usedforcommunicationdirectlythrough
RS232.Whenemptyinthetable,theprocesshastobedeterminedfromtheFLOW‐BUSsystem
information(forparameterslocatedinmorethanoneprocess,e.g.setpoint,measure).
FBnr(parameter) ParameternumberinprocessonFLOW‐BUSmodule, usedforcommunicationdirectlythrough
RS232.
Type Variabletypeoftheparameter
 c (unsigned)char 1byte value0..255whenStrLenis0
 c string MultiplebyteswhenStrLenisotherthan0
 i (unsigned)integer 2bytes value0..65535
 f float 4bytes value+‐1.18E‐38..+‐3.39E+38(IEEE‐floatingpointnotation)

l (unsigned)long 4bytes value0..4294967295
datatypes>1byteareMSBfirst.
StrLen Lengthofstringinbytes(characters)usedincombinationwithTypecforstrings
 ‐2 indicatesthatastringiszero‐terminated,notdefinedinlength,butuntilthefirst0‐char.
 X indicatesastringwithalengthofXbytes
 0 meansnoinfo
required(notastringtypeparameter)
Min Minimumvalueofparameterallowedwhenparameterisread/written.Thevaluewillbechecked
onthislimit(errorwhenoutoflimit).
Max Maximumvalueofparameterallowedwhenparameterisread/written.Thevaluewillbechecked
onthislimit(errorwhenoutoflimit).
Read IndicationifparameterisallowedtobereadviaFLOW‐BUS.
Write IndicationifparameterisallowedtobewrittenviaFLOW‐BUS.
Poll IndicationifparametershouldbepolledcontinuouslybyFlowDDE inordertokeepthe(changing)
parametervalueuptodate.
Advanced Indicationifparameterisforadvancedusersonly.Thesearemainlyparametersfor
maintenance/service.
Secured IndicationifparameterissecuredforusethroughFLOW‐BUS.Readingthisparameterispossible,
butchangingitneedsspecialhandling.
Highsecurity Indicationifparameterishighlysecured(onlyfewparameters).Readingthisparameterispossible,
butchangingitneedsspecialhandling.
Description Shortdescriptionaboutthe meaningofparameterorwhere itisusedfor.
DDEstr ParameterDDEstring(max.10characters).Thisbecomesthe DDEvaluewhenparameterisnot
availableoninstrument.Also:untilFlowDDEV4.58usedforparameteridentification.
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Changingparametervaluesispossiblewhenaparameterisnotread‐onlyandnotsecured.Therange
andtypeofparametersaredescribedinthetables.Whenparametervaluesareoutofrangetheywill
beeither'clipped'onthenearestvalueallowedoryouwillgetanerrormessage:'parameter
value
error'.
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(FlowDDE)Parameternumbers:
Allparameterinformationisreferencedtotheparameternumber.Thisisauniquenumberforaparametertoavoid
redundancy.ThesenumbersareneededforDDEcommunicationonly.
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