ADLINK DAQe-2502 - Manual (Page 62)

52 Operation Theory
4.5 Trigger Sources
The DAQ-/DAQe-/PXI-2502/2501 card provides flexible trigger
selections. In addition to software trigger, the DAQ-/DAQe-/PXI-
2502/2501 card also supports external analog and digital triggers.
You can configure the trigger source for A/D and D/A processes
individually via software.
NOTE A/D and D/A conversions share the same analog trigger.
Software-Trigger
This trigger mode does not need any external trigger source. The
trigger asserts right after you execute the specified function call. A/
D and D/A processes can receive an individual software trigger.
External Analog Trigger
The analog trigger circuitry routing is shown in the Figure 4-25.
The analog multiplexer selects either a direct analog input from
the EXTATRIG pin (SRC1) on the 68-pin connector CN1 or the
input signal of ADC (SRC2). The range of trigger level for SRC1 is
±10V and the resolution is 78mV (refer to Table 4-8), while the
trigger range of SRC2 is the full-scale range of AD input, and the
resolution is the desired range divided by 256.
Figure 4-25: Analog Trigger Block Diagram