This section gives an overview of how to set up a CD24 and begin recording data. We recommend that you set up a test instrument in your office or laboratory as a “dry run” to gain a basic understanding of the system and to check that it is functioning as expected.
This test installation will use the instrument's default settings. Data will be received using Güralp Systems' Scream! software, available from the website
You will need access to a PC with a 9-pin RS232 port, a 12 V power source and a working sensor (CMG-3ESP, ESPC, 40T, 6T).
Install Scream! on your PC and run it.
Connect the wire from the breakout box to the CD24's 19-pin connector.
Connect the 6-pin connector on the breakout box to the GPS unit using the GPS cable. Position the GPS so that it has a good view of the sky.
If you do not have a view of the sky, you can operate the CD24 without a GPS unit, but timing information may be inaccurate.
Connect the sensor to the 26-pin connector on the side of CD24
Connect the 6-pin data plug on the breakout box to the 9-pin RS232 port on your PC using the serial cable.
Use the power cable to connect the 10-pin power plug on the breakout box to a fused 10 – 28 V power source.
The CD24 and instrument are now fully operational, and will already be producing data.
After a few seconds you should see the CD24 digitizer appear under Network – Local – Com1 in the left-hand panel of Scream!'s main window. (If your PC has multiple serial ports, it may appear under some other Com port name.) Soon after, data streams will begin appearing in the right-hand panel. Streams with higher sample rates will appear sooner than those with lower sample rates.
If this does not happen, check all connections, and ensure the power supply is providing the correct voltage and current.
Each data stream has a Stream ID, a six-character string unique to it. Stream IDs normally identify the instrument, component and sample rate of each stream. Thus the stream 1026Z2 refers to a Z-component stream from instrument 1026, at tap 2. For more details on taps and sample rates, see section 4.1, page 39.
Data streams ending in 00 are status streams containing any extra information sent from the digitizer.
To view data, select a stream and then double-click to open a Waveview window.
You can view several streams at once by holding down SHIFT as you select, and then double-clicking the selection.
To start recording new data to a file, right-click on a stream or a selection of streams and choose Start recording from the pop-up menu. Recording settings, directories, etc., can be altered by selecting File → Setup... from the main menu and switching to the Recording tab.
To view status information, select the stream and right-click to open a pop-up menu. Select View.
The first few status blocks will consist of the CD24's start-up messages, including its software revision number and the data streams selected for downloading and triggering.
Later blocks give information on the GPS system (number of satellites visible, the location of the GPS antenna, time synchronization status, etc.) and the baud rates in use for each channel.