Figure 4-18. startscan input signal timing, Figure 4-18. startscan input signal timing -31 – National Instruments E Series User Manual
Page 67
Chapter 4 Signal Connections
National Instruments Corporation
4-31
DAQCard E Series User Manual
scan. The sample interval counter is started if you select internally
triggered CONVERT*.
As an output, the STARTSCAN signal reflects the actual start pulse
that initiates a scan. This is true even if the starts are externally
triggered by another PFI. You have two output options. The first is an
active high pulse with a pulse width of 50 to 100 ns, which indicates
the start of the scan. The second action is an active high pulse that
terminates at the start of the last conversion in the scan, which indicates
a scan in progress. STARTSCAN will be deasserted t
off
after the last
conversion in the scan is initiated. This output is set to tri-state at
startup.
Figures 4-18 and 4-19 show the input and output timing requirements
for the STARTSCAN signal.
Figure 4-18.
STARTSCAN Input Signal Timing
Rising-edge
polarity
Falling-edge
polarity
t
w
t
w
= 10 ns minimum