National Instruments 653 Series User Manual page 36

Chapter 2 Using Your NI 653X
DIO Config VI
Write?
Yes
DIO Write VI
Notes If you are using an external clock for finite pattern input, the NI 653X requires an
extra clock edge to move data from the DIO ASIC and into the computer memory after the
final data sample is acquired.
If you are performing a finite pattern output operation, you can call DIO Wait VI instead
of the DIO Write VI after the DIO Start VI. For more information about these VIs, refer to
the LabVIEW Help.
NI 653X User Manual
No
Trigger?
Yes
Digital Trigger Config VI
DIO Start VI
Figure 2-9. Programming Pattern I/O in NI-DAQ LabVIEW/LabVIEW RT API
♦
NI PCI/PXI-6534
For output buffered transfers the NI 6534 by default preloads the onboard
memory with data before starting the output operation. Preloading
eliminates or reduces the impact of the PCI bus bandwidth limitations and
increases the overall transfer rate. The preloading process causes a small
delay between the start command in software and the actual start of data
transfer. If this is a concern, you can disable the preloading by calling the
following function/VI before the software start command:
• NI-DAQ C interface—In the
set the
ND_FIFO_TRANSFER_COUNT
• LabVIEW—Use the DIO Parameter VI to set the Scarabs Preload
Enable attribute to None.
Digital Trigger Config VI
Yes
No
Set_DAQ_Device_Info
2-16
DIO Clear VI
No
Trigger?
Yes
No
Done?
DIO Read/Write VI
function,
to .
ND_NONE
ni.com