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MELSEC-Q
10 DEVICES
Interrupt counters
(1) Definition
Interrupt counters are devices which count the number of interrupt factor
occurrences.
(2) Count processing
(a) The interrupt counter's current value is updated when an interruption
occurs. It is not necessary to create a program which includes an interrupt
counter function.
(b) Interrupt counter operation requires more than the simple designation of a
set value.
To use the interrupt counter for control purposes, comparison instructions
(=, <=, etc.) must also be used to enable comparisons with the set value,
with an internal relay (M), etc., being switched ON or OFF according to the
comparison result.
The figure below shows a sample program in which M0 is switched ON
after 10 interrupt inputs are performed. (In this example, "C300" is the
interrupt counter No. corresponding to I0.)
= K10 C300
M0
(3) Setting the interrupt counter
(a) In order to use interrupt counters, at first interrupt counter No. setting must
be designated at the "PLC system" tab screen in the “(PLC) Parameter"
dialog box.
256 points are then allocated for interrupt counters, beginning from the "first
counter No." which is designated.
If C300 is designated as the first interrupt counter No., numbers C300 to
C555 will be allocated for interrupt counters.
I0
I1
I2
I255
C300
C301
C302
C555
Interrupt counter (256 points)
Values corresponding to the interrupt counter No.
(b) In order to use an interrupt counter, an "interruption permitted" status must
be established by E1 instruction at the main routine program.
Содержание QCPU (Q Mode)
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