User`s manual

Operation Theory 29
DAQ/PXI-2500 SERIES can generate standard and arbitrary
functions, continuously or piece-wisely. Appendix A demon-
strates possible wave-form patterns generated by DAQ/PXI-
2500 SERIES in combination with various counters, clock
sources, and voltage references.
Software Update
This method is suitable for applications that need to generate D/A
output controlled by user programs. In this mode, the D/A con-
verter generates one output once the software command is
issued. However, it would be difficult to determine the software
update rate under a multi-task OS like Windows.
Waveform Generation
This method is suitable for applications that need to generate
waveforms at a precise and fixed rate. Various programmable
counters will facilitate users to generate complex waveforms with
great flexibility.
There are three event signals involved in Waveform Generation:
Start, DAWR (DA WRite), and Stop. Please refer to Table 4.2.2 for
a brief summary on Waveform Generation Events and their corre-
sponding Trig-ger Sources.
For more information on Trigger Mode, Stop Mode, Time-base,
and Trig-ger Sources, please refer to sections 4.2, 4.1, and 4.5,
respectively.
-FSR + LSB -Vref * (2046 / 2048) Vref * ( 1 / 4096) 0001
-FSR -Vref 0 0000
Signal Descriptions Valid Sources
Start Start Waveform Generation process.
Software Trigger
Ext. Digital Trigger
Analog Trigger
SSI Trigger
Table 4-6: Trigger Signals and Corresponding Signal Sources
Table 4-5: D/A Output Versus Digital Codes