Measurement Computing WaveView - Manual (Page 24)

WaveView, pg. 22 03-05-02 WaveView
Acquisition Configuration
Reference Note:
For additional trigger-related information refer to the WaveBook User’s Manual chapter entitled,
WaveBook Operation Reference.
General Information
You can access the Acquisition Configuration dialog box
from the main window’s View pull-down menu or toolbar.
The Duration column has text-boxes for pre-trigger scans,
post-trigger scans, and convention (number of scans or
time period).
The following formula determines the maximum number of
scans that can be stored for use in the Scope mode.
This does not apply to storage to disk.
(Scan duration) * (# of Channels) * 4 < Available PC Memory
A scan includes all channels that are set to “On” in the
analog input configuration spreadsheet.
The Rate column allows you to set pre-trigger and
post-trigger scan rates. Timebase settings can be for
Frequency or Period.
Timebase units are as follows:
Frequency - Hz, kHz, or MHz.
Period - seconds, milliseconds, or microseconds.
The scan rate can also be driven by the External clock of
the digital input port. With this option, enabled scans occur
as pulses are input on the external clock pin. The scan rate
is set as a fraction of the external clock rate by the Clock
Divider setting. The fastest scan rate is obtained from a
clock divider setting of 1. A setting of 10 would take one
scan every tenth pulse.
Acquisition Configuration (Internal Clock)
Note: The check-box for “Use Post-Trigger rate for
Readings Column acquisitions” is, by default,
not checked. The option is intended for WBK17
counter mode applications and forces
WaveView’s Readings column to update at the
Post-Trigger rate.
Acquisition Configuration (External Clock)
In addition to the acquisition configuration aspects just discussed, WaveBook/516, /512A, and /516A
include a pin for receiving external clock input, a counter-timer, Digital-Pattern Trigger, and a Pulse
Trigger. Since these features do not apply to the WaveBook/512 or /512H, they are discussed separately in
the following section.