Programming instructions

Chapter 20 Special Programming Considerations for SCXI
© National Instruments Corporation 20-5 LabVIEW Data Acquisition Basics Manual
SCXI Settling Time
The filter and gain settings of your SCXI modules affect the settling time
of the SCXI amplifiers and multiplexers. You should always enter your
jumpered filter settings and your jumpered gain settings (if applicable) in
the configuration utility. LabVIEW uses the gain and filter settings to
determine a safe interchannel delay that allows the SCXI amplifiers and
multiplexers to settle between channel switching before sampling the next
channel.
LabVIEW calculates the delay for you. If you set a scan rate that is too fast
to allow for the default interchannel delay, LabVIEW shrinks the
interchannel delay and returns a warning from the AI Start or AI Control
VIs. You can refer to your hardware manuals for SCXI settling times.
You can open the advanced-level AI Clock Config VI to retrieve the
channel clock selection. Set the
which clock
control to
channel clock 1
,
and set the
clock frequency
to –
1.00
(no change). Now run the VI. The
actual clock rate specification
cluster is on the right side of the panel.