Using the DM24
4 Using the DM24
Once the DM24 is connected to your equipment, it will start producing data
immediately. You can now start configuring it for your own needs. There are two
ways you can do this:
•
using the graphical interface provided by Scream!, or
•
over a terminal connection (see Chapter 6 on page 56).
Both methods provide full access to the major configuration options of the digitiser.
In most circumstances, you will use Scream! to operate the system. For complete
information on how to use Scream! to configure and control your instrument, please
refer to the Scream! user guide.
4.1 Taps
The DM24 converts analogue signals to digital data at a high sample rate, which is
then reduced in steps. This process is known as
decimation
, and each output stage
is called a
tap
. Taps are numbered from zero – the highest sample rate – upwards.
The highest data rate you can choose is 1000 samples/s. This rate can only be
produced by Tap 0, the first tap. Tap 0 can alternatively produce data at 500, 400, 200
or 100 samples/s.
After Tap 0 there are three more taps. Each tap produces data at an integer sample
rate, which must be 2, 4, 5, 8 or 10 times lower than the previous tap.
For example, the following is a possible sequence:
•
Tap 0 : 500 samples/s
•
Tap 1 : 50 samples/s (divide by 10)
•
Tap 2 : 10 samples/s (divide by 5)
•
Tap 3 : 5 samples/s (divide by 2)
The digitiser always generates all four sample rates, but it does not have to output
them. You can configure any set of taps to output. You can also have different taps
configured for different sensor components.
All of these configuration options are easily changed via Scream!, or you can use the
terminal commands
SET-TAPS
and
CONTINUOUS
.
16
Issue U - December, 2021
