4. Functions
CNT32-4MT(LPCI)
47
Control of a counter
Counter start/Counter stop
The counters on the board can be started and stopped individually for each channel or globally for all
channels. The table below lists the counter start and stop triggers. Which triggers to use can be selected
by software.
Table 4.1. Counter operation
Item Factor
Description
Note
Software command
(for all/each of channels)
Possible to start the counter for all or
each of the channels.
Rise of control input
signal
The counter is started at a level change
(low-to-high transition).
Available only when the
control input signal has been
selected for counter
start/stop.
Fall of control input
signal
The counter is started at a level change
(high-to-low transition).
Available only when the
control input signal has been
selected for counter
start/stop.
Counter start
trigger
Sampling start
Sampling start = counter start
Software command
(for all/each of channels)
Possible to stop the counter for all or each
of the channels.
Rise of control input
signal
The counter is ended at a level change
(low-to-high transition).
Available only when the
control input signal has been
selected for counter
start/stop.
Fall of control input
signal
The counter is ended at a level change
(high-to-low transition).
Available only when the
control input signal has been
selected for counter
start/stop.
Counter stop
trigger
Sampling stop
Sampling stop = counter stop
0
Software
The counter is started or stopped by software either for each channel or for all channels.
Rise/fall of an external input signal
The counter is started or stopped by an external input signal supplied through the control input pin. The
rising or falling edge of the signal can be selected for starting or stopping the counter. If the
“low-to-high” transition is set for both starting and stopping the counter, the counter is started or stopped
if it is inactive or active, respectively, when the level changes from low to high.
* When the control input pin is used for the counter start/stop signal, it cannot be used for the preset,
zero-clear, or general-purpose input.
Sampling start/stop
When the counter start trigger is used for starting sampling, the board starts counting and sampling
synchronously. When the counter stop trigger is used for stopping sampling, the board stops counting
and sampling synchronously in the same way.
