NI DAQ 6052E, Руководство пользователя

Страница: 69 / 132

Chapter 4 Connecting the Signals
© National Instruments Corporation 4-31 NI 6052E User Manual
Figure 4-22. STARTSCAN Output Signal Timing
The CONVERT* pulses are masked off until the device generates
STARTSCAN. If you use internally generated conversions, the first
CONVERT* appears when the onboard SI2 counter reaches zero. If you
select an external CONVERT*, the first external pulse after STARTSCAN
generates a conversion. Separate the STARTSCAN pulses by at least one
scan period.
A counter on the device internally generates STARTSCAN unless you
select some external source. The TRIG1 signal starts this counter, and
the application software or the sample counter stops it.
Scans generated by either an internal or external STARTSCAN are
inhibited unless they occur within a sequence. Scans occurring within
a sequence can be gated by either the hardware AIGATE signal or the
software command register gate.
STARTSCAN
a. Start of Scan
t
w
= 50 to 100 ns
t
w
Start Pulse
CONVERT*
STARTSCAN
b. Scan in Progress, Two Conversions per Scan
t
off
= 10 ns minimum
t
off