ADLINK PXI-2006 - Manual (Page 67)

Operation Theory 57
Mode 8: Continuous Gated Pulse Generation
This mode generates periodic pulses with programmable pulse
interval and pulse-width following the software-start.
GPTC_GATE is used to enable/disable counting. When
GPTC_GATE is inactive, the counter halts the current count
value. Figure 4-30 illustrates the generation of two pulses with
a pulse delay of four and a pulse-width of three.
Figure 4-30: Mode 8 Operation
4.5 Trigger Sources
We provide flexible trigger selections in the DAQ/PXI-20XXseries
products. In addition to the internal software trigger, DAQ/PXI-
20XX also supports external analog, digital triggers and SSI trig-
gers. Users 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 4 channel inputs you can select as a trigger source). Both trig-
ger sources can be used for all trigger modes. The range of trigger