4. Function
40
CNT24-4(PCI)H
Single-phase Input
For a single-phase input, the count increments when an UP pulse is inputted and decremented when a
DOWN pulse is inputted. The count remains unchanged if UP and DOWN pulses are inputted
simultaneously.
6
7
8
5
7
6
* Count operation for incremental counting in the CW direction.
When decremental counting in the CW direction is set,
the PC Card performs decremental counting at the rising edges of positive pulse
and incremental counting at the rising edges of negative pulses.
UP pulse
(Phase-A/UP)
DOWN pulse
(Phase-B/DOWN)
Count value
Figure 4.2. Example counting during single-phase input
Single-phase Input with Gate Control
The counter can be started and stopped by using a gate control signal along with the single-phase pulse
stream.
7
8
6
9
Series of single-phase
pulses (Phase-A/UP)
Gate control signal
(Phase-B/DOWN)
* Count operation for incremental counting in the CW direction.
When decremental counting in the CW direction is set, the PC Card performs decremental
counting at the rising edges of the single-phase pulse train (phase-A/UP) while the gate control
signal (phase-B/DOWN) goes high and stops counting while the gate control signal goes low.
No counting
Count value
Figure 4.3. Example counting during single-phase input with gate control
