Toshiba nv Series - Application as a Slave Counter with Alarm

3.3. Operation of the slave counter
8ch Pulse Input Module PI918 Functional Manual
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3.3.2. Application as a slave counter with alarm
Theslavecountercountsandholdstheexternalinputpulsesofthe
slavesidechannelsinsynchronizationwiththeinterruptofthemaster. 
Therefore,itcanbeusedforrelativemeasurementofpulsespeedratio
(frequencyratio)withrespecttothemasterchannel.
Condition:
Parameter
setting
EP AL SP SV
1 1 0 1
External
input
Pulseinput Gateinput
Externalpulseconnection Invalid

Operation:
(1 Thecounterisresetwhenthegateconditionofthemaster
becomes"Permission."
(2) Theinterruptstatusisinversedasynchronouslywhenanoverflow
oftheslavecounteroccursduringgatepermissionofthemaster.
(3) Thecountvalueistransferredtotheholdregisterandthecount
valueisresetto"0"whenaninterruptoccursinthemaster.  When
theholdvaluealarmvalue,thestatusoftheslaveisinversedin
synchronizationwiththechangeinthemaster'sinterruptstatus.
(4) Thecountvalueistransferredtotheholdregisteratthegate
prohibitionconditionofthemaster.


Figure 3.3.2. Example of slave counter with alarm operation
0
Mastercounter
(autoreset
mode)
Slavecounter
Xm
Slaveholdvalue
0
A
B
C
D
E
F
Masterinterrupt
status
Mastergate
condition
A
0
B
Masterholdvalue
Slaveinterruptstatus
Xs
Overflow
G
C
D
E
F
G
(Permission
)

Alarm
(Synchronousinversion)
(Asynchronous
inversion)