User`s manual

36 Operation Theory
Waveform Generation Timing
Six counters interact with the waveform to generate different
DAWR timing, thus forming different waveforms. These are
described in Table 4-7.
NOTE The maximum D/A update rate is 1 MHz. The minimum
UI_counter setting is 40.
Counter Name Width Description Note
UI_counter 24-bit
Update Interval, which
defines the update inter-
val between each data
output.
Update Interval =
UI_counter / Time-base*.
UC_counter 24-bit
Update Counts, which
defines the number of
data in a waveform.
When value in UC_counter
is smaller than the size of
waveform patterns, the
waveform is generated
piece-wisely.
IC_counter 16-bit
Iteration Counts, which
defines how many times
the waveform is gener-
ated.
DLY1_counter 16-bit
Define the delay time for
waveform generation
after the trigger signal.
Delay Time =
(DLY1_counter / Clock
Timebase)
DLY2_counter 16-bit
Define the delay time to
separate consecutive
waveform generation.
Effective only in Iterative
Waveform Generation
mode.
Delay Time =(DLY2_counter
/ Clock Timebase)
Trig_counter 16-bit
Define the acceptable
start trigger count when
re-trigger function is
enabled
Timebase*=40M for DAQ/
PXI-2500 Series
Table 4-7: Summary of Counters for Waveform Generation