Waveform Generation Timing Signals; D/A Start Trigger Signal; D/A Convert Signal - Measurement Computing PCI-DAS6031 User Manual

PCI-DAS6031 & PCI-DAS6033 User's Guide

Waveform generation timing signals

The signals that control the timing for the analog output functions on the PCI-DAS6031 are listed below.
! D/A START TRIGGER
! D/A UPDATE
! D/A EXTERNAL TIME BASE

D/A START TRIGGER signal

The D/A START TRIGGER signal is used to hold off output scans until after a trigger event. The DAQ-Sync
"DS D/A START TRIGGER" input or any AUXIN pin can be programmed to serve as the D/A START
TRIGGER signal. It is also available as an output on any AUXOUT pin.
When used as an input, the D/A START TRIGGER signal may be software selected as either a positive or
negative edge trigger. The selected edge of the D/A START TRIGGER signal causes the DACs to start
generating the output waveform.
The D/A START TRIGGER signal can be used as an output to monitor the trigger that initiates waveform
generation. The output is an active-high pulse having a width of 50 ns.
Figure 4-24 and Figure 4-25
signal.
Rising Edge Polarity
Falling Edge Polarity

D/A CONVERT signal

The D/A CONVERT signal causes a single output update on the D/A converters. You can program the DAQ-
Sync DS D/A UPDATE input or any AUXIN pin to accept the D/A CONVERT signal. It is also available as an
output on any AUXOUT pin.
The D/A CONVERT input signal polarity is software selectable. DAC outputs update within 100ns of the
selected edge. The D/A CONVERT pulses should be no less than 100 µs apart.
When used as an output, the D/A CONVERT signal may be used to monitor the pacing of the output updates.
The output has a pulse width of 225 ns with selectable polarity.
show the input and output timing requirements for the D/A START TRIGGER
Figure 4-24. D/A START TRIGGER input signal timing
t
w
Figure 4-25. D/A START TRIGGER output signal timing
4-14
t
w
t = 37.5 ns minimum
w
t
w
= 50 ns
Functional Details