User`s manual

CYDAS UDR Library User’s Guide Analog Input Boards - UMDAS 0802HR
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Event notification
Even notification functions and methods supported
UDR:
cbEnableEvent(), cbDisableEvent()
UDR for .NET:
EnableEvent(), DisableEvent()
Event types:
ON_SCAN_ERROR, ON_DATA_AVAILABLE, ON_END_OF_AI_SCAN
Hardware considerations
Acquisition rate
Since the maximum data acquisition rate depends on the system connected to the UMDAS 0802HR, it is
possible to “lose” data points when scanning at higher rates. The CYDAS UDR Library cannot always detect
this data loss.
Most systems can sustain rates of 80 kS/s aggregate. If you need to sample at higher rates than this, consider
using the
BURSTIO option explained above.
BURSTIO
BURSTIO
mode allows higher sampling rates for sample counts up to the size of the FIFO. The UMDAS
0802HR device's FIFO holds 32,768 samples. Data is collected into the device's local FIFO. Data transfers to
the PC don't occur until the scan completes. For
BACKGROUND scans, the Count and Index returned by
cbGetStatus() and GetStatus() remain 0, and Status=RUNNING until the scan finishes. The Count and
Index are not updated until the scan is completed. When the scan is complete and the data is retrieved,
cbGetStatus() and GetStatus() are updated to the current Count and Index, and Status = IDLE.
BURSTIO is required for aggregate Rate settings above 100 kHz, but Count is limited to sample counts up to
the size of the FIFO (32,768 samples).
Count settings must be an integer multiple of the number of channels
in the scan.
EXTCLOCK
You can set the SYNC pin (pin 36) as a pacer input or a pacer output from InstaCal. By default, this pin is set
for pacer input. If set for output, using the
cbAInScan / AInScan option, EXTCLOCK results in a BADOPTION
error.
Continuous scans
When running cbAInScan() with the
CONTINUOUS option, you should consider the packet size and the number
of channels being scanned. In order to keep the data aligned properly in the array, make the total number of
samples an integer multiple of the packet size and the number of channels.
When running cbAInScan() with the CONTINUOUS option, you must set the count to an integer multiple of the
packet size (31) and the number of channels in the scan.
Miscellaneous functions and methods supported
UDR:
cbFlashLED()
UDR for .NET:
FlashLED()
Causes the LED on a USB device to blink.
When you have several USB devices connected to the computer, use these functions to identify a particular
device by making its LED blink.