Easy Electronics xLogic Micro PLC - Page 178

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referencedanalogmathfunctionblock.
ParameterReferencedFB
ThevaluefortheReferencedFBparameterreferencestheblocknumberofanalready-programmed
analogmathfunctionblock.
Descriptionofthefunction
Theanalogmatherrordetectionblocksetstheoutputwhenthereferencedanalogmathfunctionblock
hasanerror.Youcanprogramthefunctiontosettheoutputonazerodivisionerror,anoverflowerror,
orwheneithertypeoferroroccurs.
Ifyouselecttheautomaticallyresetcheckbox,theoutputisresetpriortothenextexecutionofthe
functionblock.Ifnot,theoutputretainsitsstateuntiltheanalogmatherrordetectionblockisresetwith
theRparameter.
Inanyscancycle,ifthereferencedanalogmathfunctionblockexecutesbeforetheanalogmatherror
detectionfunctionblock,theerrorisdetectedinthesamescancycle.ifthereferencedanalogmath
functionblockexecutesaftertheanalogmatherrordetectionfunctionblock,theerrorisdetectedinthe
nextscancycle.
Analogmatherrordetectionlogictable
Inthetablebelow,ErrortoDetectrepresentstheparameteroftheanalogmatherrordetection
instructionthatselectswhichtypeoferrortodetect.Zerorepresentsthezerodivisionbitsetbythe
analogmathinstructionattheendofitsexecution:1iftheerroroccurred,0ifnot.OFrepresentsthe
overflowbitsetbytheanalogmathinstruction:1iftheerroroccurred,0ifnot.ZerodivisionOROverflow
representsthelogicalORofthezerodivisionbitandtheoverflowbitofthereferencedanalogmath
instruction.Output(Q)representstheoutputoftheanalogmatherrordetectionfunction.An “x”
indicatesthatthebitcanbeeither0or1withnoinfluenceontheoutput.
Errorto
Detect
zero of Output
Zero
division
1 X 1
Zero
division
0 X 0
Overflow X 1 1