Omron CJ1W-CT021 Operation Manual page 97

Output Control
3.2-kHz
pulse
Comparison
Data 0
Counter Value
matches Target
Value
Note Precautions When Setting Comparison Data
•
Comparison Stoppage When Comparison Target Reached
When the High-speed Counter Value reaches the target value for Comparison
Data, comparison stops for 1.5 ms. However, comparison for other counters
does not stop.
Set the Comparison Data considering the time when the comparison is
stopped.
For example, for the Comparison table shown in the following diagram, approx-
imately 4.8 counts occur during 1.5 ms when a 3.2 kHz pulse is input. This
means that comparison does not occur for Counter Values 101, 102, 103, and
104. During this period, the Output set under the Output Pattern does not turn
ON.
Comparison starts again after this 1.5 ms has elapsed.
At this time, the processing returns to the stoppage period and Comparison
Data 1 and 2 are executed at the same time.
100 101
Comparison
Data 1
Comparison is stopped for 1.5 ms.
Outputs set under the Output Pattern will not turn ON
during this period even if the Counter Value equals the
Target Value.
•
Comparison Stoppage for IOWR- and IORD-instruction Execution
Comparison is stopped during the execution of IOWR/IORD-instructions and
remains stopped until the processing of the instruction has been completed.
The Data Transfer Busy bit is ON during this time.
This stopping of comparison during the execution of IOWR/IORD-instructions
affects Counter comparisons for all counters.
In contrast to Range Data, comparison occurs once during the stoppage
period after the Data Transfer Busy bit turns OFF.
However, when Comparison Data is rewritten using an IOWR-instruction, the
Comparison Result is refreshed using the new Comparison Data and the cur-
rent Counter Value, which means the result of the comparison during the stop-
page is not reflected.
Refer to Appendix E "IORF and IOWR/IORD-instruction Execution Times" for
information on execution times for IOWR/IORD-instructions.
Note 1. Multiple Comparison Values of a specific Counter may not have the same
value. The Unit will generate an error if multiple CV's have the same value
(refer to 5-2 "Error codes" for more details).
2. CV-Data can also be changed on the fly. Refer to 4-3 "IOWR-Instruction" for
more details.
3. The Digital Outputs are Set/Reset in the chronological order of reaching the
CV's. After reaching a (new) CV the (old) Unit Output Pattern is updated.
102 103
Comparison
Data 2
Counter Value
104 105
Section 3-5
77