ADLINK PXI-2502 - Manual (Page 36)

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• Operation Theoreym
DAQ/PXI-2500 SERIES can generate standard and arbitrary functions,
continuously or piece-wisely. Appendix A demonstrates possible wave-
form patterns generated by DAQ/PXI-2500 SERIES in combination with
various counters, clock sources, and voltage references.
4.2.1 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 converter 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.
4.2.2 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 corresponding Trig-
ger Sources.
For more information on Trigger Mode, Stop Mode, Time-base, and Trig-
ger Sources, please refer to section 4.2.2.2, 4.2.2.4, 4.1.4.2, and 4.5, re-
spectively.
Signal Descriptions Valid Sources
Start
Start Waveform Generation
process.
Software Trigger
Ext. Digital Trigger
Analog Trigger
SSI Trigger
DAWR
Write data to the DAC on the fal-
ling edges of DAWR.
Internal Update
External Update
SSI Update
Stop Stop Waveform Generation
Software Trigger
Ext. Digital Trigger
Analog Trigger
Table 4.2.2 Trigger Signals and Corresponding Signal Sources