ADLINK PXI-2208 - Manual (Page 83)

Operation Theory 71
4.5 Trigger Sources
ADLINK provides flexible trigger selections in the DAQ-/DAQe-/
PXI-2204/2205/2206/2208 card. In addition to the internal soft-
ware trigger, the DAQ-/DAQe-/PXI-2204/2205/2206/2208 card
also supports external analog, digital triggers, and SSI triggers.
You can configure the trigger source by software for A/D and D/A
processes individually. Note that the A/D and the D/A conversion
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 calls
to begin the operation. 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 4-31.
The analog multiplexer can select either a direct analog input from
the EXTATRIG pin (SRC1 in Figure 4-31) in the 68-pin connector
or the input signal of ADC (SRC2 in Figure 4-31). That is, one of
the four channel inputs you can select as a trigger source. Both
trigger sources can be used for all trigger modes. The range of
trigger level for SRC1 is ±10V and the resolution is 78mV (refer to
Table 4-6), while the trigger range of SRC2 is the full-scale range
of the selected channel input and the resolution is the desired
range divided by 256. For example, if the channel input selected to
be the trigger source is set bipolar and ±5V range, the trigger volt-
age would be 4.96V when the trigger level code is set to 0xFF
while -4.96V when the code is set to 0x01.