
B-61813E/03 CONNECTIONS 8. HIGH SPEED COUNTER MODULE
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2) PRS (preset signal)
The PRS signal presets data in registers. If data is set in
DTOH, DTOM, and DTOL and then PRS is reversed, the
data is set in the register specified by SELECT. Reversing
the PRS signal means that PRS changes from level 0 to level
1 or vise versa.
DTOH, DTOM, DTOL, and SELECT should not be changed
within two scans after the PRS is reversed. Also, the PRS
must not reversed again within this period.
When SELECT=1, data is set in both the counter preset
register and the counter.
Data is set by setting the first PRS to 1 after power-on or after
the mode changesto B.
3) CE (count enable signal)
The CE signal determines whether the counter counts. When
the CE is set to 1 and the external input signal CSP closes the
contact, the counter retains its value, instead of counting.
When CE = 1 and the CSP external input contact is open, the
counter counts input pulses. Presetting the counter requires
maintaining CE = 0.
4) MS (marker synchronization signal)
The MS signal determines whether marker synchronization
is provided. When the MS is 1 and the the contact of external
input signal ME is closed, the counter is preset to the value in
the counter preset register at the rising edge of the
firstmarker signal. If the MS is set to 0 then set to 1 or the
MHR is set to 1 then setto 0, marker synchronization is
provided again.
(The MHR signal is not included in mode B.)
5) MHR (marker hold reset signal, only in mode A)
The MHR signal resets the marker hold (MH) signal which is
output to the PMC. TheMHR is set to 1 to reset the marker
hold signal.
6) CMA, CMB, and CMC (comparison mode signals A, B, and
C, only in mode A)
The CMA, CMB, and CMC signals specify the levels of the
comparison outputs A, B, and C (CMPA, CMPB, and
CMPC), respectively.
When CMA, CMB, and CMC are 0, and the value of the
counter is larger than the values in comparison registers A, B,
and C, CMPA, CMPB, and CMPC are set to 0.
When CMA, CMB, and CMC are 1, and the value of the
counter is equal to or less than the values in comparison
registers A, B, and C, CMPA, CMPB, and CMPC are set to
1.