User manual

Chapter 4 Connecting Signals
NI 6034E/6035E/6036E User Manual 4-28 ni.com
Figure 4-20. STARTSCAN Output Signal Timing
The CONVERT* pulses are masked off until the device generates the
STARTSCAN signal. If you are using internally generated conversions, the
first CONVERT* appears when the onboard sample interval counter
reaches zero. If you select an external CONVERT*, the first external pulse
after STARTSCAN generates a conversion. The STARTSCAN pulses
should be separated by at least one scan period.
A counter on your NI 6034E/6035E/6036E device internally generates the
STARTSCAN signal unless you select some external source. This counter
is started by the TRIG1 signal and is stopped either by software or by the
sample counter.
Scans generated by either an internal or external STARTSCAN signal are
inhibited unless they occur within a DAQ sequence. Scans occurring within
a DAQ sequence may be gated by either the hardware (AIGATE) signal or
software command register gate.
STARTSCAN
a. Start of Scan
t
w
=50to100ns
t
w
Start Pulse
CONVERT*
STARTSCAN
b. Scan in Progress, Two Conversions per Scan
t
off
= 10 ns minimum
t
off
UM.book Page 28 Monday, May 14, 2001 10:32 AM