Chapter 3
Hardware Overview
©
National Instruments Corporation
3-15
the full-scale range of the selected channel, and the resolution is that
range divided by 256 for the AT-MIO-16E-1, AT-MIO-16E-2, and
AT-MIO-64E-3, and divided by 4,096 for the AT-MIO-16XE-10 and
AT-AI-16XE-10.
Note
The PFI0/TRIG1 pin is a high-impedance input. Therefore, it is susceptible to
crosstalk from adjacent pins, which can result in false triggering when the pin is left
unconnected. To avoid false triggering, make sure this pin is connected to a low-impedance
signal source (less than 10 k
Ω
source impedance) if you plan to enable this input using
software.
Figure 3-8.
Analog Trigger Block Diagram
There are five analog triggering modes available, as shown in Figures 3-9
through 3-13. You can set
lowValue
and
highValue
independently in
software.
In below-low-level analog triggering mode, the trigger is generated when
the signal value is less than
lowValue
.
HighValue
is unused.
Analog
Input
Channels
PFI0/TRIG1
PGIA
+
–
ADC
DAQ-STC
Analog
Trigger
Circuit
Mux