Omega Vehicle Security 1400 User Manual

Configuration Aspects for Programmers

ChartScan User’s Manual

B-5

 

 The High-speed, single-channel mode, also known as burst mode, is used for post-acquisition waveform
analysis of AC and DC voltages.  In this mode, ChartScan can sample from 38.5 Hz to 20.0 kHz, and store the
data in memory.  Note that ChartScan’s memory can be expanded up to 8 Mbytes.
 When performing post-acquisition waveform analysis, such as Fast Fourier transforms, ChartScan can return
each data point in a waveform.  In addition, ChartScan can provide the true RMS value of an AC voltage.
 Because high sampling rates can be achieved in the High-speed, single-channel mode, the conditions indicated
in the following table apply.
 

 

 

 

 

 

High/Low./Last registers

 

Disabled

 

Alarms

 

Disabled

 

Trigger Start

 

Software trigger only (@ command)

 

Trigger Stop

 

By Count only

 

Pre-Trigger

 

Disabled

 

Post Stop Count

 

Disabled

 

Time Stamping

 

Disabled

 

Alarm Stamping

 

Disabled

 

Digital Input Stamping

 

Disabled

 

Averaging weight

 

256, forced default (can not be changed)

 

Frequency

 

In regard to AC voltage, frequency must be such
that it results in a sufficient whole even number of
samples per line cycle.

 
 ChartScan collects samples for the selected channel in blocks of 256 samples in one time increment.  This
appears similar to a scan of 256 channels while in the normal (multiple-channel) mode since you must …
•  program the number of 256 sample blocks to acquire in the post trigger count parameter of the 

Y

 command,

and will

•  retrieve the data from ChartScan as “post trigger count” scans of 256 samples

High-speed, single-channel mode is a “one-shot” operation.  It permits ChartScan to collect the
specified number of samples, then stops.  The mode is not continuous, nor does it allow for memory
overflow and wrap-around.  The maximum number of samples is limited by the amount of memory
available.  See the 

Y

 command reference (in Appendix A) for related information.

In regard to AC voltage measurements, ChartScan only supports AC voltages having an input signal
frequency which is an integer multiple of the AC line cycle.  In order to compute an accurate RMS
value you must program a frequency which will yield a sufficient “whole even number” of samples per
line cycle.

In High-speed, single-channel mode, upon completion of the acquisition, AC voltage RMS values can
be retrieved with the 

U17

 query command.

To use the High-speed, single-channel mode use the following commands, or use ChartView  (see Chapter 4).
Note that these commands (or ChartView equivalent) are all that is needed to initiate the High-speed, single-
channel mode data acquisition.