Omron CQM1H - PROGRAM Programming Manual page 61

Interrupt Functions
36
High-speed Counter 0 Interrupt Count
For high-speed counter 0 interrupts, a comparison table is used instead of a
"count up." The count check can be carried out by either of the two methods
described below. In the comparison table, comparison conditions (for compar-
ing to the PV) and interrupt subroutine combinations are saved.
Method
Target value A maximum of 16 comparison conditions (target values and count
directions) and interrupt subroutine combinations are saved in the
comparison table. When the counter PV and the count direction match
the comparison conditions, then the specified interrupt routine is exe-
cuted.
Range com- Eight comparison conditions (upper and lower limits) and interrupt rou-
parison tine combinations are saved in the comparison table. When the PV is
greater than or equal to the lower limit and less than or equal to the
upper limit, then the specified interrupt subroutine is executed.
Target Value Comparisons
The current count is compared to the target values in the order that target val-
ues are set in the comparison table and interrupts are generated as the count
equals each target value. Once the count has equaled all of the target values
in the table, the target value is set to the first target value in the table, which is
again compared to the current counted until the two values are equal.
Count
Initial value
Target value
Range Comparisons
The current count is compared in cyclic fashion to all of the ranges at the
same time and interrupts are generated based on the results of the compari-
sons.
0
1
Note When performing target value comparisons, do not repeatedly use the INI
instruction to change the current value of the count and start the comparison
operation. The interrupt operation may not work correctly if the comparison
operation is started immediately after changing the current value from the pro-
gram. (The comparison operation will automatically return to the first target
value once an interrupt has been generated for the last target value. Repeti-
tious operation is thus possible merely by changing the current value.)
Operation
Interrupts
1 2 3 4 5
3
2 4
Section 1-4
Comparison Table
Target value 1
Target value 2
Target value 3
Target value 4
Target value 5
Comparison Table
Rage setting 1
Rage setting 2
Count
Rage setting 3
Rage setting 4