ADLINK PXI-2502 - Manual (Page 50)

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• Operation Theoreym
4.5 Trigger Sources
We provide flexible trigger selections in DAQ/PXI-2500 SERIES. In addi-
tion to software trigger, DAQ/PXI-2500 SERIES also supports external
analog and digital triggers. Users can configure the trigger source for A/D
and D/A processes individually via software.
NOTE: A/D and D/A conversion share the same analog trigger.
4.5.1 Software-Trigger
This trigger mode does not need any external trigger source. The trigger
asserts right after users execute the specified function call. A/D and D/A
processes can receive an individual software trigger.
4.5.2 External Analog Trigger
The analog trigger circuitry routing is shown in the Figure 4.5.1. The analog
multiplexer selects either a direct analog input from the EXTATRIG
pin( SRC1 in Figure 4.5.1) on the 68-pin connector CN1 or the input signal
of ADC( SRC2 in Figure 4.5.1). The range of trigger level for SRC1 is ±10V
and the resolution is 78mV(please refer to Table4.5.1), while the trigger
range of SRC2 is the full-scale range of AD input, and the resolution is the
desired range divided by 256.
AIn Instrumentation
Amplifier
A/D
Converter
Input Multipexer CN1
MUX Analog
Trigger
Circuit
EXTATRIG
SRC1
SRC2
Figure 4.5.1 Analog trigger block diagram