Measurement Computing WaveView - Manual (Page 27)

WaveView 03-05-02 WaveView, pg. 25
WaveView can be configured to read only the low word of the counter data (CtrLo:“On,” CtrHi: “Off”).
This decreases the minimum scan period by 1 usec. This LoCtr only option can be used only when the
external clock frequency is greater than 305 Hz (20,000,000 MHz / 65536]. Note that WaveView does not
enforce this.
Digital-Pattern Trigger
In addition to digital trigger, each WaveBook/512A, /516, and /516A supports a digital-pattern trigger.
This expanded capability allows data collection to start when a user-defined 16-bit digital pattern is
matched on the digital I/O connector. This feature is useful when trying to capture noise, vibrations or
some other physical disturbance that occurs at a particular point in a digitally-sequenced process (from a
PLC or relay-logic-control system).
When “Digital Pattern” is selected as the Triggering Type, the 16-bit pattern extension appears (as indicated
in the following figure). The Condition box allows the following choices:
Equal To (=) / Not Equal To (< >) – These options treat each digital line as a separate input to be
compared to logical 1 or 0. Selecting “Equal To” triggers only on the exact pattern of 1’s and 0’s selected.,
while “Not Equal” triggers on all others. You can also set any of the inputs to “don’t care” (X), which
excludes it from the comparison.
Greater Than (>) / Less Than (<) – These options interpret the digital inputs as a single 16-bit value and
allow a threshold trigger.
Acquisition Configuration Dialog Box, with Digital Pattern Extensions
Note: The “Internal” and “External” buttons in the top row of the dialog box are used
to select Internal Clock, or External Clock, respectively.