Chapter 16. Inside Scream!
16.1 Command line options
Options can be prefixed with either a hyphen - or a forward slash / in both Windows and Linux versions. The option names are case insensitive.
-view filespec [filespec…] : Launch in data viewer mode. The files or directories specified are scanned and displayed in a single WaveView window. Whilst Scream! is scanning the files, a small window displays the progress and estimated completion time.
A WaveView window in data viewer mode is identical to a real-time WaveView window, except that
The data are not held in memory (although memory equivalent to around 10% of the file size is used to store summary data). When you change the displayed time range by zooming in or out, panning, or resizing the window, Scream! re-reads the data for the new time range.
The advantage of this approach is that you can view files in data viewer mode which are larger than the amount of memory available. Scream! in real-time mode can only draw blocks which are kept in its memory buffer (see section 6.4.1).
You cannot return to the Main Window by clicking on the stream identifier in the context menu.
You cannot drag streams from one WaveView window to another one (unless one was created as a duplicate of the other), or from a viewer-mode window to a real-time Scream! application window.
Everything on the command line after -view is treated as a file specifier. If you need to issue other options, place them before -view.
-i:configuration-file : Use configuration-file instead of scream.ini to load Scream!'s settings.
-FlashLED : Flash the Scroll Lock keyboard LED each time a block is received.
-NoSplash : Do not display Scream!'s splash-screen at startup.
-V31 : Force network packets to be in Scream! 3.1 format. Since Scream! 4.n is backwards compatible with Scream! 3.1, you should not need to use this option.
-disknn:image-file : Treat the file image-file as a raw DFD disk, attached to port nn.
-noaspi : On Windows 98, 95 and ME, Scream! uses the Adaptec ASPI drivers provided with the operating system to control SCSI devices. On other operating systems, the ASPI drivers are not available, so Scream! controls the devices directly. Use this switch to force Scream! to control devices directly even if the ASPI drivers are present.
16.2 The calvals.txt file
If a file named calvals.txt exists in the same directory as Scream!'s executable (scream.exe), Scream! will look there for suitable calibration values.
Caution: If you do not have write permission on the directory where the executable is located (which is normal), Windows may silently redirect any file access to the virtual store instead. Please see the Microsoft documentation for information about the virtual store.
Note: If an alternative location has been specified for calvals.txt by use of a parametersfile=path declaration in the [CUSTOM] section of scream.ini and a file exists in that location, Scream! will use that file and not look further. If no such declaration exists, Scream! will look in the current working directory for a file named calvals.txt. If it finds one, it will use that in preference to the one in the same directory as Scream!'s executable. Neither of these techniques are recommended because none of the supplied MATLAB® extension scripts will look anywhere other than in the standard location.
Each stream has its own section in the file, identified by its System ID and Serial Number (as described in section 5.3.1) in the format
[SystemID-SerialNumber]
Scream! and its extension scripts check to see if the streams being received match any of the instruments in the file. If they do, the software will apply the correct values for your sensor automatically.
You can edit the section of the calvals.txt file appropriate to any particular digitiser within Scream! by either:
right-clicking on the digitiser icon and selecting Calvals… from the context menu; or
right-clicking on a stream in a WaveView window and selecting Calvals… from the context menu.
The second method is the only method possible when in View mode.
The format of each section is given in section 5.7.
16.3 File and directory locations
16.3.1 Windows version
Scream! creates or uses the following files and directories
scream-directory\scream.exe : The program itself.
scream.ini : The configuration file for Scream!. If updating older installations, this file may be in the windows-directory e.g. C:\WINDOWS\scream.ini, for new installations this will be in the c:\scream\ directory. To restore the application to its factory settings, close down Scream! and delete this file.
Note: The scream.ini file can actually have any name and be in any accessible location, provided that scream is started with the -i:configuration-file option. See section 16.1 for details.
scream-directory\qtintf70.dll : The Qt shared library which Scream! requires to run.
scream-directory\calvals.txt : The sensor and digitiser calibration information file (but see the caution about the Virtual Store, above).
scream-directory\autoload\ : The directory to take auto-load GCF files from (see section 11.3).
c:\scream\data\ : The default directory for recording data. You can change this: see Chapter 11.
scream-directory\html\ : The default directory for Scream!'s online help.
c:\scream\logs\ : The default directory for log files. You can change this if you wish: see Chapter 13.
scream.rec : This file lists streams which have been manually set to be recorded. It is changed when a user sets a specific scream to be recorded or not. It is not changed when automatic recording of all streams is enabled so, if automatic recording is subsequently disabled, the original selection can be restored. This file is not always called scream.rec but it always has the same name and location as scream.ini, with the extension changed from .ini to .rec.
16.3.2 Linux version
The default installation directory - scream-directory - for the Linux version of Scream is /usr/lib/scream-4.6. The following files and directories are used:
scream-directory/scream : The program itself.
scream-directory/scream.ini : The configuration file for Scream!. To restore the application to its factory settings, close down all running copies of Scream! and delete this file.
Note: The scream.ini file can actually have any name and be in any accessible location, provided that scream is started with the -i:configuration-file option. See section 16.1 for details.
library-directory/libborqt-6.9.0-qt2.3.so : The Qt shared library which Scream! requires to run.
scream-directory/calvals.txt : The sensor and digitiser calibration information file.
scream-directory/autoload/ : The directory to take auto-load GCF files from: see section 11.3.
scream-directory/data/ : The default directory for recording data (you can change this: see Chapter 11.
scream-directory/html/ : The default directory for Scream!'s online help.
scream-directory/logs/ : The default directory for log files. You can change this: see Chapter 13.
scream.rec : This file lists streams which have been manually set to be recorded. It is changed when a user sets a specific scream to be recorded or not. It is not changed when automatic recording of all streams is enabled so, if automatic recording is subsequently disabled, the original selection can be restored. This file is not always called scream.rec but it always has the same name and location as scream.ini, with the extension changed from .ini to .rec.
16.4 Common issues
A number of configuration or operational issues can produce error messages. The most common are described below.
Scream! has not been able to retrieve the current configuration from a digitiser. This can happen because
The device is not connected.
The communications link is one-way (simplex). Scream! needs reliable two-way communications to discover the digitiser's set-up. However, you can still receive data over a simplex link.
The device is heavily loaded, and Scream! times out waiting for a response from it.
The network between Scream! and the computer hosting the device is slow or unreachable. You can check this using the standard command ping ip-address to check that the remote computer is responding.
If your computer is on the same network as the remote device, it must be on the same subnet as that device, or it will need to connect through a gateway machine.
It is recommended that you wait for data to be received from the digitiser before you attempt to configure it.
The Scream.ini file could not be opened for writing. This can happen because
The file or disk are write-protected.
You do not have the right privileges to change the file.
The file is in use by another program.
An instance of Scream! is already running on your system, and is using the referenced ini file for it's configuration. You cannot run two instances of Scream! using the same configuration file. You should either return to the running instance, or if you intended to start a second instance of Scream, you need to specify a different configuration file. See the -i option in section 16.1.