7. DATA CAPTURE
The Dash 16u has 512 kSamples per channel of high-speed RAM for data capture. In order to capture data, a trigger must
be produced. For each record, pre- and post-trigger data can be captured. You must select the conditions under which
you will capture data (trigger set up) as well as how you will collect the data (number of samples per second and for how
long). Further, within the data capture record, you can pick where the trigger point will be placed.
Note that in the Dash 16u, the RAM memory is volatile which means that if the recorder is powered down, or loses power,
the data captures still resident in the RAM will be lost. The Dash 16u does have a battery back-up for power, therefore in
the event of a power loss, the user still has time to archive the data capture in the RAM to the Zip disk.
SETUP DATA CAPTURE
[SYS] [SETUP DATA CAPTURE]
There are seven parameters for setting up data capture:
[SET SAMPLE RATE]
Use the encoder wheel to select how many samples per second you will take.
[SET RECORD SIZE]
Use the encoder wheel to select how much memory you will use. To help you
decide, the length of capture (time duration) is shown. Pick enough memory to
give you enough recording time.
[SET TRIGGER WINDOW]
Use the encoder wheel to select where within the capture the trigger will be. In
addition to Start, Center and End, the trigger can be any percentage value of the
record. By placing the trigger point at any value other than Start, you will record
pre-trigger data.
[SET OPERATION]
You can capture one record only (single capture) or capture one record only and
play it to the chart (single capture and playback). Select multi-capture with or
without playback to capture more than one record. With multi-capture, the Dash
16u re-arms itself, waiting for the next trigger.
[SET CHANNELS TO STORE]
Select the channels to be captured.
[ADVANCED]
Format capture memory. Data record I/O to Zip disk. Select auto-trigger to
dictate whether or not the data record is automatically triggered when the Dash
16u is armed (
[ARM]
key). Select auto-backup of records to Zip disk.
SETUP TRIGGER
[SYS] [SETUP TRIGGER]
Once the data capture is set up, select the conditions under which you will take
data. In addition to auto-trigger listed above, there are four other ways to trigger
a capture:
[MANUAL]
When activated, the
[TRIG]
key on the Dash 16u will produce a trigger.
[WAVEFORM]
When activated, a change in signal level will produce a trigger:
[SYS] [SETUP TRIGGER] [SETUP WAVEFORM]
. Pick the channel(s) to
set up and how it will trigger:
[SET TYPE / CLASS]
. When more than one
channel will be used for triggering, you can select OR or AND combinations.
Each channel's trigger levels are independent of the other channels. You can use
window triggering (either inside or outside the window), level triggering (above
or below the level) and slope triggering (rising, falling or either slope).
