Appendix F: PIA Trouble shooting

Purpose

The purpose of this chapter is to give the user of the PHT Interactive Analysis hints on what to do if he runs into trouble or in the event of S/W crash. This might happen due to wrong installation or due to the fact that PIA is still under development or just because it is a very complex piece of code and beyond a certain complexity level of a software it becomes very hard to rule out all bugs.

General Procedure

If you come across a serious problem while using PHT Interactive Analysis, the following steps should be taken:

Please check first the following section and the part of this manual relating to the action you were trying to perform when the problem occurred and try to find out as far as possible yourself whether the problem is already known or due to wrong usage and whether a solution to your problem is described in this manual.

If you are sure that you cannot cope with the problem yourself and that the problem is not described here, i.e. you are sure that you really have discovered a bug within PIA, please write a problem report. Please write down as detailed as possible what you were trying to do when the problem occurred, describe all important steps you have performed before the error showed up, name the data set that was in use when the error was detected, describe the error itself and, very important, copy any error message that you have got from idl on the prompt you have started PIA from into a file. Finally send this file via E-mail to: cgabriel@iso.vilspa.esa.es

Known Problems and Solutions

The missing calibration file problem

Problem: During a certain processing step or during startup PIA crashes with a message like this:

% FXBOPEN: Unable to open file /home/idt/cg/ia/cal/PDIE1TRANS.FITS

Solution: Errors like this indicate that the PHT Interactive Analysis software is either missing a calibration file (CAL-G, CAL-Q or CAL-U) or the user does not have read access to the directory which holds these files: CALDIR. This error can occur if the PIA software has been updated, but the calibration files related to the new version were not entered in the related directory. Ensure that the user has read access to the directory CALDIR and that this directory contains the latest version of all CAL-G, CAL-Q and CAL-U files used by PIA. You can find lists of these files in Table 2 "Calibration Filename Conventions (Calibration G Files)" on page 12, Table 3 "PHT Uplink Tables generated by PIA (Calibration U Files)" on page 12 and in Table 4 "RTA/QLA Calibration Files (CAL-Q) generated by PIA" on page 13.

The pht_fm.idb_def transfer problem

Problem: Due to the specific format of the pht_fm.idb_def file, the file is sometimes corrupted during electronic file transfer. This makes PIA crash when house keeping data shall be displayed (HK button), because PHT house keeping data are converted by using the information in the pht_fm.idb_def file.

Solution: Ensure that the latest version of pht_fm.idb_def is installed in the CALG directory. In case problems occur, compare the length of the file in byte with a working version (distribution version) in order to make sure that no corruption during file transfer has occurred.

The hidden window problem

Problem: Certain warning windows or small input windows block the rest of PIA. As this is not normally the case for other PIA applications, it can lead to confusion, especially when parts of PIA are iconized and the screen is very crowded with applications.

Solution: In cases where PIA applications look blocked, check the IDL prompt for a crash, and, if no indication for a crash is indicated, open all iconized windows in order to check if any of them is waiting for an input, before killing the PIA process. You can use the help of a window manager tool installed under the Control button in the PIA top window.

The colour table problem

Problem: The PHT Interactive Analysis uses a special colour table within idl. The use of other colour-intensive X-applications (like e.g. NETSCAPE), which were started on the same terminal or console before the PIA session was started, can cause the colour table to change randomly when entering or leaving certain windows with the mouse pointer. Normally the actual performance of PIA is not disturbed, however, it can be very annoying.

Solution: If you feel very disturbed by this, exit all X-applications before starting PHT Interactive Analysis on your terminal.

The printer problems

  1. Problem: PIA crashes when trying to print. This could be due to the fact that the user hasn't got a write access to the directory PIA_PRINTDIR or to the file idl.ps, which is a temporary file which is overwritten when PIA performs a print-out. This error can be caused if several users use the same directory PIA_PRINTDIR. In this case the file idl.ps is generated when the first user first starts a print job under PIA, causing this file to have his/her user id and default access rights. This normally blocks the write access of other users.


    2. Solution: In order to solve this problem please change the file access for the group and owner of this file (idl.ps) in such a way that all users of PIA who share the PIA_PRINTDIR read and write have access to it.

  2. Problem: No output on my printer after a print command.


    3. Solutions:

What to do after a crash in order not to avoid losing your data

As the PHT Interactive Analysis software holds a lot of information in large internal buffers, a crash of PIA does not necessarily mean the complete loss of all data that have been processed so far. Please note that the procedure described in this section is only the last resort. There is no guarantee that it will actually work, because a crash of PIA can (but need not) destroy the contents or parts of the contents of the PIA buffers. In general it is a saver procedure to always store all intermediate products at the moment they are generated in order to have them available for later use, not only after a crash.

After you have followed the instructions under "General Procedure" of what to do after a crash has occurred, you can try the following steps in order to recover your data:

  1. Close the window from which you triggered the action leading to the crash with the QUIT button.
  2. Store all the interesting data currently in the internal PIA buffer in either internal or external files. Do not overwrite existing data files as the data you are writing now might be corrupted by the crash.
  3. Leave PIA using the QUIT button
  4. Leave IDL by: IDL> exit
  5. Restart IDL and PIA
  6. Read back the data you have saved
If PIA behaves normally during the read process of step 6) and the further processing, the recovery action was successful. Otherwise there is no other way than to start the processing again from the beginning.


 
History of this Section:
Date  Authors  Description 
04/07/1995  Ingolf Heinrichsen(MPIK)  First Version 
22/07/1996  Carlos Gabriel(ESA-SAI)  General Update 
16/02/1998 Carlos Gabriel(ESA-SAI)  Update (V7.0)