Toshiba nv Series - Application as a Universal Counter with Alarm

3.1. Operation of the universal counter
8ch Pulse Input Module PI918 Functional Manual
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3.1.4. Application as a universal counter with alarm
Aninversionoftheinterruptstatusbitoccurswhenthecountreaches
thealarmvalue,andthecountiscontinued.  Thealarmvaluecanbe
overwrittenasneeded.
 Condition:
Parameter
setting
EP AL SP SV
1 1 0 0
External
input
Pulseinput Gateinput
Externalpulseconnection
ONlevel,orbatch
permission
(GEN=‘1’)

 Operation:
(1) Externalinputpulsesarecounted.  Aninversionoftheinterrupt
statusbitoccurswhenthecountreachesthealarmvalue.  For
alarmvaluesof8001htoFFFFh,nointerruptconditionoccurs. For
analarmvalueof8000h(32768),aninterruptoccursat"0"count.
(2) Thecountiscontinuedregardlessofthealarmvaluesetting
outsidetheinterruptoccurrencepermissionperiod(gate
permission),butnointerruptoperationisperformed.
(3) Thecountervalueistransferredtotheholdregisterwhenthegate
inputconditionincludingcommandchangesfromPermissionto
Prohibition.
Figure 3.1.4. Example of universal counter with alarm operation
Interruptoccurrencepermission(GateON,
Command'1')
Gate&command
Externalinput
p
ulse
Countvalue
32767
Interruptstatus
A
B
D
C
E
Valuetransferred
tothehold
register
(Note) AtoEinthefigureshowalarmvalues,andthevaluesarechangedforeach
interruptintheexampleshown.  Ifthealarmvalueisrewrittentoavaluebelow
thecountvaluewhenthecountvalueisbelowthealarmvalue,aninterruptoccurs
immediately.
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