VI Logger error: Database does not exist in the specified path

[Tom_W_[DE]]

Hi Richard-

Let me know if I can help with any other questions.  Thanks a lot-

[Nicholas_B]

steorn:

Can you tell us exactly what three paths you changed in the Registry Editor?

Thanks,

N. Butler

National Instruments

[Georgesk]

Hello Voltage,

I am trying to install VI Logger Lite for a set of machines in such a way that it can be restored via disk images managed by a server (based on Rembo software, http://www.rembo.com/products_autobackup.htm). Restoring machines is necessary because we are working in an academic environment, teaching physics to  15 years old students. Each machine can be used by more than twelve different students each week. Our laboratory is considered as reliable since we restore the disks at each bootup, hence the number of students using its facilities.

The installation of NI software and VI Logger Lite on the first "standard" machine succeeded, without worry. So this image was uploaded to the server and as there was no evident problem it replaced the former one. However our lab technician and me falled into a lot of trouble as we tried to use the disk image from the standard machine to configure the other machines in the laboratory.

We found that there was a wrong link to a  database, pointed out as \\mendeleiev\etc. , "mendeleiev" being the name of the standard machine. So we uninstalled every NI software from the standard machine, deleted evry subdirectory related to NI, and uploaded the new image to the server. Unfortunately this results in the error message "Database does not exist in the specified path", when we try to install the software on whichever machine in our laboratory, which is quite puzzling. It appears that we deleted a subdirectory _mendeleiev_, and that the string "mendeleiev" remains in Windows' register.

We tried various hacks to build again a consistent image without reference to the previous installations, without success.

So here comes the question:

is it possible to have a database not dependent on the network name of the computer ? A reference to c:\physic_data would be appreciated for example. If there are some configurations necessarily tied to an individual machine, what is the minimal set of changes to perform in order to transform a common disk image to fit an individual machine? We can forge these changes if we know which they are, via the netlogon script.

Thank you for any advice.

Best regards,                                        Georges.

[Ryan_V[DE]]

Georges,

There is a key in the registry called 'HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger\Default database'. Have you tried setting it to '\\localhost\VI Logger Data'? localhost is the keyword which refers to "this machine." This points VI Logger to the database. It is the responsibility of the database server to save the data to a certain directory on disk. I would suggest starting with a fresh image, and making sure that this is the value for the key. Please let us know if this works for you.

Hope this helps,

[Georgesk]

Thank you for your kind answer, Voltage.

I understood the following from what you wrote :
1- there must already be an entry "HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger" in the registry
2- This entry must contain the key "HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger\Default database" set to "\\localhost\VI Logger Data"
3- VI Logger must be installed again when this key is set in such a fashion.

----> some context: I install Vi Logger _Lite_ on a standard machine, aiming to make a disk image redistributable to 19 other machines, used by students aged 15-20. We currently use about 60 different educational applications, and a machine can be accessed by a dozen of different students each week.

So here is what I did today:
1- I fetched an old disk image with no past installation of NI products, compatible with my standard machine and booted it up.
2- I installed VI Logger
3- I uninstalled Vi Logger
4- I modified the key "HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger\Default database", replacing the string "mendeleiev" by "localhost"
5- I installed again Vi Logger.

Unfortunately it made no difference: the directory c:\Program Files\National Instruments\Vi Logger\Shared\Citadel\_LocalCache contains a subdirectory named _mendeleiev_. This subdirectory is locked by one ore many applications when Windows is running, and its contents are locked too.

So I made a copy of the subdirectory _mendeleiev_ and renamed the copy as _localhost_, Checked that the key "HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger\Default database" still pointed to localhost, uninstalled Vi Logger and installed it again.

Without success!

The directory locked by running processes is always _mendeleiev_, _localhost_ is not considered by the running applications. When I run a task, the former subdirectory is not touched.

Every test I made to delete or to rename directly the directory _mendeleiev_ when it was not locked (upon uninstallation of Vi Logger) resulting in the decieving message "Database does not exist in the specified path" when Vi Logger was installed again and an new task ran.
And I made loads of tests! When the directory _mendeleiev_ is deleted, the installation process never rebuilds this directory (why???) so the error is sticky.

-----

My provisional conclusion is the following :
- either there is a reference to mendeleiev in some non-human-readable format, hidden in some file under the directory c:\Program Files\National Instruments or in the register, and this reference survives an uninstall/reinstall cycle,
- either the path to the database is established in reference to the machine's name, whatever the key "HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger\Default database" may specify. A generic reference as "localhost" is not considered.

As we bought 20 interfaces, to be used by students on as many machines, I shoud highly appreciate to learn a way to be able to install the necessary software without losing all the effort which was input in the creation of the current good disk images, which our colleagues appreciate a lot.

I thank you in advance for any useful hint about it.

Best regards,                                      Georges.

[Ryan_V[DE]]

Georges,

I'm currently investigating a workaround for this issue. Your patience is greatly appreciated.

Regards,

[Georgesk]

Hello Voltage,

thank you in advance for keeping investigating about this issue.

am I wrong if I suppose that the difficulty comes from the fact that VI Logeer is a subproduct of Labview, not a standalone program ?

our need may be fullfilled by a driver of a lower level (not depending on database stuff ,nor sockets etc.). If I could find a code snippet
demonstrating how to launch a finite set of analogic measurements and retrieving the results if would be sufficient. We already wrote
various simple programs to feed experimental data into text files, or pipe them into other processes, so this part is not a problem.
The database feature coming with VI Logger, probably useful with Labview, is not required in our context. As soon as we have a simple
way to feed data into the program Regressi (http://perso.wanadoo.fr/jean-michel.millet/), which is well understood by every young
student, we are happy.

Best regards,            Georges.

[Ryan_V[DE]]

Georges,

We have found a work-around! Please complete the following tests and let us know if this works.

1. Install VI Logger Lite, reboot
2. Create a new DAQmx Task and a new VI Logger Task
3. Log some data, close VI Logger
4. Move the C:\Documents and Settings\All Users\Application Data\National Instruments\VI Logger folder to another place, such as C:\VI Logger Data. Make sure it no longer exists in the C:\Documents and Settings\All Users\Application Data\National Instruments\ path.
   
5. Change computer name
6. Reboot
7. Launch VI Logger. Attempt to access one of the data runs you logged in step 3. You will receive some error about the database.  Choose to select another database.
   
8. The database browser window will appear. Right-click on My Computer and choose Create/Attach. Browse to the path where you put the database files in step 4. After you browse to the database, notice that the dialog box as chosen a database name for you.  For example, if you had placed the database in C:\VI Logger Data, the default name would be something like c___VI_Logger_Data. Edit the default name to something that is easier to read, like VI_Logger_Data (the use of underscores is preferred), then click OK or Create.
9. Close VI Logger
10. Run regedit, then browse to HKEY_LOCAL_MACHINE\SOFTWARE\National Instruments\VI Logger and set the value of Default database to "\\localhost\VI_Logger_Data" (or whatever you named the database in step 8).
11. Open a command prompt window to the C:\Program Files\National Instruments\VI Logger\ path, then execute "rtask -r"  (This step may not be necessary).

After following the above steps you will be able to view any old data associated with existing VI Logger tasks. You will not be able to use the existing tasks to log new data (You get the "Database does not exist in the specified path" error). You can create new VI Logger task and log data. Also, you may be able to modify this process slightly if you receive the database error with existing VI Logger data that you wish to keep. In this case, start with step 4.

Good luck!

[Ryan_V[DE]]

Georges,

Actually, this process works as long as you keep the computer name constant (after renaming it). I still get the error when I change the name to something else after the process. You would want to do this process on each computer after deploying the images. Please let us know your results.

Regards,

[Georgesk]

Hello Voltage,

thank you for your investigations. The problem is that the disk image of computers accessed by students is renewed at each bootup, which means that this image may be renewed as much as four or five times each day. The proces is quick: provided there are few differences between the current disk and the image to paste on it... the payload is approximately one minute at each bootup, the reward is many minutes spared because there are no spyware/virii eating up the machine power.

However if we have to repeat the steps of localisation of the database, there is no benefit.