'Read JPEG File.vi' does not seem to work on PXI with real-time OS

[JanB]

I am trying to read a jpeg file on a PXI system with LabVIEW real-time on it. To test I created a very simple VI (attached) with only 4 objects: 'Path' --> 'Read JPEG File.vi' --> 'Draw Flattened Pixmap.vi' --> 'Picture'.

This VI works fine on my Windows XP host machine, but it does not work on the PXI system. The error code 1 occurs in 'Read JPEG File.vi'.

The jpeg picture is in the same directory as the VI. I don't think I got the path or filename wrong because if I change the file or path name I get another error: 7: 'File/Directory Info in Check Path.vi->Read JPEG File.vi->test.vi'.

Maybe reading jpeg files is not supported on realtime systems? I could not find anything about it. Sol
utions or workarounds are of course welcome!

[JR_A.]

'Read JPEG File.vi' is not supported on LabVIEW RT. I believe it has to do with special functions or libraries need to be called due to the JPEG image type. Instead you can use a Bitmap and the 'Read BMP File.vi', which I believe is completely implemented in G code.

Keep in mind that the RT System doesn't really have a front panel and that the front panel is only 'available' when LabVIEW is connected to the target such as being targeted or having a remote panel to it. Generally, a deployed RT system doesn't have a UI and just communicates to a Host VI which acts as the UI. Having said that, the BMP file worked when I tested.

Regards,

JR A.

[JanB]

Ok. Thanks for the clear answer. I will try to find something that first converts the JPEG images to BMP images before they are uploaded to the RT system.

[TOBBR]

Having the same problem here.

I want to upload a jpg per FTP from my webcam to my fieldpoint system an display the picture in a remote panel. But as read jpg is not supported by RealTime OS it is not working so far.

Anyone got some ideas or a workaround for that?

[Devin_K]

TOBBR,

As mentioned by JR A. above, the RT environment does not support opening JPEG files.  I tried an alternate solution using the VIs from the IMAQ driver, and had no success with that either.

If possible, I would recommend converting your webcam image to a BMP on your host before FTPing it over to your target.