Operation Modes - Data Translation DT9850 Series User Manual

Operation Modes

DT9850 Series modules support the following digital I/O operation modes:
• Single-value operations – Use software to specify the DIN or DOUT subsystem, the
resolution (8), and the gain (1) of the subsystem. Data is then read from or written to the
appropriate digital I/O lines.
Single-value operations stop automatically when finished; you cannot stop a single-value
operation.
Note: Although single-value operations are the simplest to use, they do not allow you to
check the interrupt status; use continuous digital input mode, described next, to check the
interrupt status.
• Continuous digital input operations – Allow you to read digital input values and check
the interrupt status of the digital input port.
Use the Open Layers Control Panel applet to select any of the first seven digital input lines
to perform interrupt-on-change operations; refer to
interrupts and to
pull-down.
Use software to specify DIN subsystem element 1, continuous mode, the resolution (8),
and the trigger source (software).
Once the operation is configured and started, an event is generated when digital input
line 0 to 6 of the digital input port changes state. Using software, 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 am interrupt-on-change 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 byte of the first word of lParam contains the state of the digital input subsystem,
where bit 0 corresponds to digital input line 0 and bit 6 corresponds to digital input line 6.
The high byte of the first word of lParam contains the digital lines (bits) that changed state
causing the interrupt to occur, where bit 8 corresponds to digital input line 0 and bit 14
corresponds to digital input line 6.
page 38 for information on configuring the digital inputs for pull-up or
page 27 for information on enabling
Principles of Operation
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