National Instruments Isolated Analog Input Device NI PXI-4224 - Manual (Page 62)

Appendix B Timing Signal Information
NI PXI-4224 User Manual B-6 ni.com
Figures B-7 and B-8 show the input and output timing requirements
for AI SAMP CLK.
Figure B-7. AI SAMP CLK Input Signal Timing
Figure B-8. AI SAMP CLK Output Signal Timing
The AI CONV CLK pulses are masked off until the device generates
AI SAMP CLK. If you use internally generated conversions, the first
AI CONV CLK appears when the onboard SI2 counter reaches zero.
If you select an external AI CONV CLK, the first external pulse after
Rising-Edge
Polarity
Falling-Edge
Polarity
t
w
= 10 ns minimum
t
w
b. Scan in Progress, Two Conversions per Scan
Start Pulse
AI CONV REF
AI SAMP CLK
t
off
= 10 ns minimum t
off
t
w
= 50 to 100 ns
t
w
a. Start of Scan
AI SAMP CLK