Omron CP1H CPU UNITS - PROGRAMMING 05-2007, Operation Manual

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High-speed Counters
Section 5-2
sequently, when the Reset Bit is turned ON in the ladder program, the phase-
Z signal does not become effective until the next PLC cycle.
Software Reset The high-speed counter's PV is reset when the corresponding High-speed
Counter Reset Bit goes from OFF to ON.
The CPU Unit recognizes the OFF-to-ON transition of the High-speed
Counter Reset Bit only at the beginning of the PLC cycle during the oversee-
ing processes. Reset processing is performed at the same time. The OFF-to-
ON transition will not be recognized if the Reset Bit goes OFF again within the
same cycle.
Note (1) The comparison operation can be set to stop or continue when a high-
speed counter is reset. This enables applications where the comparison op-
eration can be restarted from a counter PV of 0 when the counter is reset.
(2) When using analog input/output (XA type only) or pulse output 2/3, pay
attention to the possibility that it may take up to 100µs to reset the existing
value of the high-speed counter due to Z-phase signal (reset input) of the
high-speed counter 3.
(3) When the counter mode is set to incremental pulse and numeric range
mode to ring mode, pay attention to the possibility that it may take time to
reset the existing value of the high-speed counter due to Z-phase signal
(reset input).
One cycle
Phase-Z
Reset Bit
PV not
reset
PV not
reset
PV
reset PV
reset
PV
reset PV
reset
One cycle
Reset Bit
PV not
reset PV
reset PV not
reset PV not
reset