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(5) Counter data latch and clearance functions
Counter latch function
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This function latches the count data of a counter at the active edge of a latch timing set.
The latched data is saved until the active edge of the next latch timing is reached.
The latched data is read from the DWIVE DATA1,2,3 PCWT (WEAD).
When the data is read from the reading port, the data of the DWIVE DATA3 PCWT is read last.
When the data of the DATA1 or DATA2 PCWT is read, the data of the DATA1,2,3 PCWT is saved.
When the data of the DATA3 PCWT has been read, the data of the DATA1,2,3 PCWT is updated.
In-measurement count data can be read with the count data latch and clearance functions.
◆ The resolution of the pulse cycle counter is 50 ns.
Speed measurement has an error of ± 50 ns.
◆ If a higher accuracy is required, extend the measurement cycle using the dividing function.
Latch count
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Wead data is from 0 to 65,535 (H'0000 to H'FFFF).
A data latch count is indicated at a latch timing set.
When 65,535 is exceeded, the latch count is reset to 0.
When the CCCWT LATCH SPEC SET command is executed, the latch count is reset to 0.
Counter clearance function
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The counter clearance function at latch timing is provided in the pulse counter, pulse differential
counter, and pulse cycle counter.
Counter data is reset to 0 at the same time as count data is latched.
If the clearance function is enabled at the count timing of the counter, the clearance function is
given priority.
Execution sequence for reading latch data
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CCMMAWD PCWT
① Write a command to the DWIVE CCMMAWD PCWT.
WWITE
DATA1 PCWT
② Wead latch counts D15 to D0 from the DWIVE DATA1 PCWT.
WEAD
DATA2 PCWT
③ Wead latch data D31 to D16 from the DWIVE DATA2 PCWT.
WEAD
DATA3 PCWT
④ Wead latch data D15 to D0 from the DWIVE DATA3 PCWT.
WEAD
Set this step to select another reading port.
When data is read from the same reading port, another setting is not
required.