National Instruments E Series - Manual (Page 62)

Chapter 4 Signal Connections
DAQCard E Series User Manual 4-26  National Instruments Corporation
SCANCLK Signal
SCANCLK is an output-only signal that generates a pulse with the
leading edge occurring approximately 50 to 100 ns after an A/D
conversion begins. The polarity of this output is software-selectable
but is typically configured so that a low-to-high leading edge can clock
external analog input multiplexers indicating when the input signal has
been sampled and can be removed. This signal has a 400 to 500 ns
pulse width and is software enabled. Figure 4-12
shows the timing for
the SCANCLK signal,
Figure 4-12. SCANCLK Signal Timing
t
w
t
w
= 400 to 500 ns
t
d
= 50 to 100 ns
t
d
CONVERT*
SCANCLK