Contec PIO-16, Руководство пользователя

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4. Function
PIO-16/16RY(PCI)
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CAUTION
- If you set the digital filter time, the filter applies to all input pins. You cannot apply the filter only to
a specific filter.
- Do not set Setting Data to a value outside the above range as doing so can cause the board to
malfunction.
Interrupt Control Function
The board can use all the input signals as interrupt request signals.
The board can generate an interrupt request signal to the PC when the input signal change from OFF to
ON or from ON to OFF.
When the digital filter (described above) is used, interrupt requests are generated by input signals that
have passed through the filter.
Disabling/Enabling Interrupts
Interrupt mask bits can be used to disable or enable the individual bits for interruptions.
Once a certain bit has been interrupt-disabled, no interrupt occurs even when the corresponding input
signal changes its level.
To let interrupts occur, enable the corresponding interrupt mask bit for interruptions.
CAUTION
All of the interrupt mask bits are interrupt-disabled when the power is turned on.
Selecting the Interrupt Edge
Interrupt edge select bits can be used to set the input logic for interruption bit by bit.
If you set an interrupt edge select bit to 0, an interrupt occurs when the input value to the corresponding
bit changes from 0 to 1 (at the transition of the input signal from OFF to ON).
If you set an interrupt edge select bit to 1, an interrupt occurs when the input value to the corresponding
bit changes from 1 to 0 (at the transition of the input signal from ON to OFF).
CAUTION
When the power is turned on, all of the interrupt edge select bits are set to 0 so that an interrupt
occurs when the input value changes from 0 to 1 (at the OFF-to-ON transition of the input signal).
Clearing the Interrupt Status and Interrupt Signal
Interrupt status bits are used to identify the input signal bit being used for requesting an interrupt.
When an interrupt status is input, the interrupt request signal and the interrupt status are cleared
automatically.
CAUTION
- All of the interrupt status bits are set to 0 when the power is turned on.
- If an interrupt mask bit has been set to disable interrupts, the interrupt status bit is not set even when
the input signal changes its level.