Backup File in cRIO Controller

[RoadKamelot]

Hi Everyone

Im working with a LVRT application that includes signal monitoring and these values are sending to a SQL database server (online).

My customer ask me if is possible to save a "backup" file into the cRIO controller, this file is going to be created if there's an error while the DB connection, when the status becomes "ok" again (after a desconnection) i need to release the back up file and send the data to the SQL server.

What's the best way to do that? I mean the best way to save data into a cRIO controller. I read a little of TDMS but i'm not sure about how to write the correct path to save the file into the cRIO.

btw: Im using NI cRIO 9074

Best Regards 

RK

[nathand · Accepted solution]

File paths in RT are the same as they are in Windows, at least as far as your LabVIEW code is concerned. The cRIO's drive is C:. You can create a folder on that drive (either programatically or using an FTP client) and then store your backup/temporary file in it.

As for the choice of file format, that's up to you. Text, binary, TDMS, whatever is convenient for your application. However, the flash drive on a cRIO has a limited number of write cycles (somewhere between 100,000 and 1,000,000) so you may not want to write to it constantly at high frequency. If you're only doing this when there's a connection error, and those error don't occur frequently, then I wouldn't worry about it.

[RoadKamelot]

Thnks for the advice related to the # of write cycles I'll take it into consideration!

btw I solved my trouble saving the back up in *txt thats because the TDMS files are longer than *txt or *dat. 

I have another question about the number of write cycles. This # is related to the application or is the limit in the cRIO? I mean what happnd if I spend the all # of write cycles? Should I buy another cRIO  ...?

Thnks

Liz RK

[nathand]

The limit on the number of write cycles is per cell within the disk. You can perform many more writes than that on the drive so long as they aren't all to the same location. Sorry if I wasn't clear about that. I'm not sure what happens when one goes bad, I've yet to have that happen. There's some good information at http://www.ni.com/white-paper/10126/en

[RoadKamelot]

Thnks a lot!

I have a last question to do. Is it possible to use the connectivity toolkit in RT??.

Actually I made my app for the host computer but the real app needs to be in RT or FPGA. I've worked with RT and FPGA modules in many apps before and also DB SQL,mySQL, and others... but this is my first database app in embedded systems.

If not, there's one way to do that? 

[nathand]

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RoadKamelot wrote:

I have a last question to do. Is it possible to use the connectivity toolkit in RT??.

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Hoping someone else can answer this, as I've never used the connectivity toolkit on any platform.

If you can't find the answer through either web searches or trying it, you might want to post it in a new thread with a subject line that reflects the actual question.

[deppSu]

I don't think so. As far as I know the database connectivity toolkit supports only windows platform.

[RoadKamelot]

You're right. Actually Im looking for a different way to send my data to the hosting.

The hosting is in another city and it dosn't have any NI software installed, it's kind of a storage space in the "cloud". By the way, the host computed only has SQL server installed.

I developed the application in my personal computer (thats why I wrote about de DB connectivity toolkit) but the originall app needs to be embedded in the cRIO and as i know the DBCT is only for windows for the activex controllers, that's why I cannot use this toolkit in my app.

Greetings!!