Contec CNT-3208M-PE, User Manual

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4. Functions
CNT-3208M-PE
47
Zero-clear
The counter is cleared to zero. Zero-clear methods are listed in the table below.
The zero-clear method is software-selectable.
Table 4.3. Zero-clear
Item Factor Description Note
Zero-clear method Software command Possible to preset for all channels Always available
Phase-Z input Phase-Z input level change Always available
Control input signal
(rise) Level change Available only when the control
input signal has been selected for
Zero-clearing.
Control input signal
(fall) Level change Available only when the control
input signal has been selected for
Zero-clearing.
Count
match(Register0) Count value = Comparison
register 0
Count
match(Register1) Count value = Comparison
register 1
Software
The counter is zero-cleared by software either for each channel or for all channels.
Phase-Z Input
The counter is zero-cleared by the external phase-Z input signal. Software is used to select positive or
negative logic and to enable or disable zero-clearing.
Rise/fall of an external input signal
The counter is zero-cleared by an external input signal supplied through the control input pin.
The control input pin is used for preset signal input. The rising or falling edge of the signal can be
selected.
* When the control input pin is used for zero-clearing, it cannot be used for the counter start/stop,
zero-clear, or general-purpose input.
Count match
The counter is zero-cleared when the count value matches the value in comparison register 0 or 1.
Register
This product has a preset register and comparison registers.
Preset Register
The preset register is a 32-bit register to load the value in the preset register to the counter when
presetting occurs.
Comparison register 0, Comparison register 1
These are 32-bit registers. A variety of events can occur when the counter value matches the value in
comparison register 0 or 1.