Data Translation DT330 Series, Руководство пользователя

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Chapter 5
60
• Continuous digital input operations – Allow you to read digital input values and check
the interrupt status of digital Port D only. You select the digital input lines to monitor for
interrupt-on-change when you configure the device driver, described on
page 27 .
Use software to specify DIN subsystem element 3, continuous mode, a resolution of 8, and
the trigger source as software.
Once the operation is configured and started, an event is generated when one of the
selected digital input lines changes state. You can then read the value of the digital input
port and determine which digital input line changed state to cause the event.
Note: If you are using the DataAcq SDK to perform a continuous digital input operation,
use the lParam parameter of the olDaSetWndHandle or olDaSetNotificationProcedure
function to determine which digital input line changed state and the status of the digital
input port when the interrupt occurred.
The low word of lParam contains the digital lines (bits) that changed state, where bit 0
corresponds to digital input line 0 and bit 7 corresponds to digital input line 0.
The high word of lParam contains the state of the digital input subsystem, where the bits
represent the digital input lines.
The resolution reflects the number of significant bits in lParam.
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