Edited on Sep 25, 2009

FAQ - Frequently Asked Questions

Questions about data collection programs (mar345, mar345dtb)

Questions about automar

Questions about PC's

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Answers to questions about data collection programs

Yes, you can. You should only update the executables with more recent ones. On our download site you will always find current program versions for download. You will have to select the executables suitable for your PC. Please see the download site for details. The executables usually will go into $HOME/bin/linux or $HOME/bin/linux/glibc-X (with X being something like 2.5) - find out by typing e.g. 'which marView' to see the executable path of program 'marView'

There are several possibilities. Each one needs to be checked:

There are further possibilities more difficult to track down like faulty hubs or broken network cables.

With the mardtb or mar345 hardware you should have obtained a CD-Rom or a tape with the original software distribution. After recalibration of the detector you should have obtained a new CD-Rom. This original software distribution can just be copied 1:1 to the home directory of the mar345(dtb) user. Make sure to select tcsh or csh as login shell for the user. If the detector has been recalibrated after its original delivery, make sure always to use the LATEST CD-Rom since with a calibration the detector specific calibration tables change. After this basic installation, feel free to update the executables from the download site as described above.

Please note, that the detector specific files for the mar345 scanner are NOT available for download due to their size (200 MB). You should backup your current software installation - at least directories MARHOME/bin, MARHOME/tables, MARHOME/log and file MARHOME/.cshrc - in regular intervals!

This typically happens when choosing illegal filenames: avoid empty spaces and special characters like star, dollar, ampersand, percent, slashes, colons and brackets.

The mar345 detector needs the erase lamps to remove residual X-rays from the image plate. In particular, the top erase lamp needs to be switched on after each read-out. You should therefore convince yourself that the erase lamps are switched on indeed after the reading head has reached the center and returns to its home position. Since the erase lamps have a very long lifetime corresponding to about 100.000 scans, it happens much more frequently, that the erase lamp sensor is broken than the erase lamp itself. With a broken sensor, you may continue data collection (even while generating warnings), but with a broken erase lamp you MUST replace it. To check the erase lamps, you will have to remove the front cover of the detector. Please consult the HOWTO_Remove_cover.pdf for instructions.

What happened is that the erase lamp sensor is broken, emitting a signal that the erase lamp itself is not functional. A broken sensor is something you can live with for a while. You should replace the sensor soon, but for now you will have to tell the mar345(dtb) program to ignore this error. Edit the configuration file located in $MARHOME/tables/config.$MAR_SCANNER_NO and insert the following line: 


		IGNORE ERROR  47  43  45

Restart the mar345(dtb) program. The program will report errors 47 (top erase lamp), 43 (left erase lamp) and 45 (righterase lamp) in the log file, but not on stdout. The data collection will not be stopped after encounting this error.

The program probably has generated an X-window exit call. This is a very sad behaviour of X-windows libraries dealing with X-window problems. In this particular case, the X application (i.e. program mar345dtb) tried to open the video stream from the TV card (frame grabber) and display it on the screen. Program mar345dtb (only versions < 8) for this purpose uses the native libXvideo interface. This library decided that it can't do it and therefore calls the exit function.

Typically, this happens if the X-configuration file /etc/X11/xorg.conf or /etc/X11/XF86Config does not load the video4linux module, which is mandatory for use of the libXvideo stuff. Please check that in section "Module" you find the entry Load "v4l" . If not, insert it and restart the X-server. The problem should be gone. If it persists, you should consider disabling the video in the mar345dtb program. For this purpose, edit file $MARHOME/tables/config.$MAR_SCANNER_NO and modify line "VIDEO USE" to "VIDEO IGNORE" and restart the program. Obviously, you won't see the crystal at all, but at least the program does not crash when going to the Crystal tab.

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Answers to questions about automar

Please run program marlicense (contained in automar package) on each computer for which you need the license and mail me the ASCII output file marlicense.$HOSTNAME produced by that program and you will get the license in return. The returned file must be gunzipped and the uncompressed file (binary, unreadable) must then be placed in /usr/local/mar on host $HOSTNAME. Alternatively, it can be placed in your home directory as: $HOME/.marlicense.$HOSTNAME.

No, you won't get a permanent license. That is the bad news. The good news is: you don't need it. See below...

No, you don't. When compiled freshly, the executables will run for 12 months. On the ftp site, the executables will be updated frequently, so typically when downloading executables from the ftp site they will continue to run for 9 to 12 months. If the temporary license has expired, it is a very good idea to download fresh executables, anyway. You can certainly expect some improvements, bug fixes, etc.

Many mar programs, i.e. all GUI's and the programs out of the automar suite (marlicense, marPeaks, marIndex, etc.) make use of system calls to obtain an IP-address, in particular routine "gethostbyname". That routine belongs to the glibc library. While automar executables are all statically compiled, they still rely on the system's glibc library. Unfortunately, glibc comes in different versions that are not always backwards compatible. For distributions relying on rpm packages (Redhat, Fedora, Suse), try "rpm -q glibc" to find out which glibc version you are running. In the mar software executable directory (bin) you will find subdirectories for several architectures. The subdirectory "linux" contains subdirectories for several glibc-versions. You will have to use executables compiled with a glibc version that is compatible to your distribution. 

		Warning: Locale not supported for XmbTextListToTextProperty
		Warning: Cannot convert XmString to compound text

The graphical user interfaces produced by Marresearch GmbH, namely programs mar345, mar345dtb, marView, marstart, automar usually are compiled on a Linux system running SuSE. While program executables are statically compiled, they do rely on certain system configurations that do differ between Linux distributions.

When running e.g. program marView on Ubuntu 6.10, you will be seeing the mentioned messages. The program will start, but text entered into text areas will not be handled correctly. This is because some components required for Motif based applications on SuSE reside in /usr/X11R6/lib/X11, but on Ubuntu 6 this lives in /usr/share/X11. Fortunately, there is a simple solution by simply setting some soft links. For programs to work on Fedora Core 5, you should do the following as super-user: 

		cd /usr/X11R6/lib/X11
		ln -s /usr/share/X11/locale .
		ln -s /usr/share/X11/XKeysymDB .
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Answers to questions about PC's

Basically, any "standard" PC will do the job. Please avoid exotic hardware like high performance video cards. The tricky part is to get the TV card to cooperate with X11. As by mid 2008, we find that only NVidia cards (or built-in NVidia chips) work with the libXvideo interface, but none of the currently available ATI cards do. Also refrain from using Intel's built-in video chips. In any case, you will have to enable the video4linux interface in the X11 configuration file as described above.

Yes, this is possible. The key thing, though, is that you can get hold of a SCSI-adapter with a 50-pin external connector. These SCSI-cards typically sell as Ultra-SCSI, not to be confused with UltraWide-SCSI. The latter ones feature 68-pin connectors. While there are SCSI-cables with a 50-pin connector on one side and a 68-pin connector on the other side, we have never been able to use them with PC hardware but only with SGI O2 (and only here by lowering the speed of the SCSI-bus). Setting up a PC for a mar180/mar300 is not as straightforward as for a mar345 detector. In case of doubt, please consider purchasing a preconfigured PC from Marresearch.

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