Omron SYSMAC CJ Series User Manual page 137

Range Comparison
The specified interrupt task is executed when the high-speed counter PV enters or leaves the range
defined by the upper and lower limit values.
• The comparison conditions (upper and lower limits and entering or leaving the range) are registered
in the comparison table along with the corresponding interrupt task numbers. The specified interrupt
task will be executed once when the high-speed counter PV enters or leaves the range.
High-speed Counter PV
Upper
limit 1
Lower
Comparison is
limit 1
executed
regardless of the
order of the ranges
Upper
limit 2
in the table.
Lower
limit 2
Interrupt task number to execute
• There are two ways to register comparison tables for range comparison. You can register a fixed-
length comparison table with eight ranges, or you can register a variable-length comparison table
with 1 to 32 ranges.
If you register a fixed-length table, the programming and data for CJ1M PLCs can be used without
modifications.
If you register a variable-length comparison table, you can register up to 32 ranges or you can regis-
ter only the required number of ranges so that less memory is used.
• The ranges can overlap.
• A different interrupt task can be registered for each range.
• The leftmost bit (bit 15) of the word containing the interrupt task number specifies if the interrupt task
is to be executed when the range is entered or left.
Bit 15 = OFF: The interrupt task will be executed when the range is entered.
Bit 15 = ON: The interrupt task will be executed when the range is left.
• The counter PV is compared with the 8 ranges or 1 to 32 ranges once each cycle.
• When the PV of the high-speed counter is changed, the applicable interrupt tasks will be executed if
the new PV falls within any table ranges regardless of whether interrupt execution is specified when
the PV enters or leaves the range.
Precautions for Correct Use Precautions for Correct Use
• When more than one comparison condition is met in a cycle, the first interrupt task in the table
will be executed in that cycle. Even if more than one comparison condition is met when the PV
enters or exits the range, the first interrupt task in the table will be executed. The next interrupt
task in the table will be executed in the next cycle.
• Once an interrupt task has been executed from a table, the interrupt task will not be executed
again for the same table until the PV enters or leaves that comparison range. However, regard-
less of whether interrupt execution is specified when the PV enters or leaves a particular
range, the Range Comparison Condition In-range Flag will be ON when the PV is within the
set range
• Even if a table range is left because the PV is reset to zero (for either a software reset or phase
Z + software reset), the applicable interrupt task will not be executed.
CJ2M CPU Unit Pulse I/O Module User's Manual
No.255 No.000 No.000 No.255
7 High-speed Counters
Comparison Table
Lower limit value 1
Upper limit value 1
Interrupt task number = 000 (8000 hex)
Lower limit value 2
Upper limit value 2
Interrupt task number = 255 (00FF hex)
Time
7
7-27