Chapter 3
Hardware Overview
©
National Instruments Corporation
3-7
Analog Trigger
In addition to supporting internal software triggering and external digital
triggering to initiate a DAQ sequence, the NI 6052E also supports analog
triggering. You can configure the analog trigger circuitry to accept either
a direct analog input from the PFI0/TRIG1 pin on the I/O connector or
a postgain signal from the output of the PGIA, as shown in Figure 3-3.
The trigger-level range for the direct analog channel is in 4.9 mV steps.
The range for the post-PGIA trigger selection is the full-scale range of
the selected channel. The resolution is that range divided by 4,096.
Note
The PFI0/TRIG1 pin is an analog input when configured as an analog trigger.
Therefore, it is susceptible to crosstalk from adjacent pins, resulting in false triggering
when the pin is unconnected. To avoid false triggering, ensure that this pin connects to a
low-impedance signal source (less than 1 k
Ω
source impedance) if you plan to enable this
input using the application software.
Figure 3-3.
Analog Trigger Block Diagram
Five analog triggering modes are available, as shown in Figures 3-4 to 3-8.
You can independently set
lowValue
and
highValue
in your ADE.
Analog
Input
Channels
PFI0/TRIG1
PGIA
+
–
ADC
DAQ-STC
Analog
Trigger
Circuit
Mux
