Using ppp on NI Linux Real-Time with a EDGE modem

[enzol]

Hi !

I try to connect a USB modem EDGE on myRIO without success.

Actually, my modem is recognized as /dev/ttyACM0 and I try to use it with ppp but it doesn't work.

ppp0 is not created when I launch pppd. I tried a lot of different configurations of ppp and none have worked.

Do you know how to configure ppp to use the modem ? There are some other thinks to install ?

Thanks a lot

[BradM]

Unfortunately, the kernel that shipped for 2013/2013sp1 does not have support for PPP enabled. Also, as I recall, you can't simply compile the support as a module and attempt to load that into the kernel, it simply changes too much regarding the kernel config such that versioned symbols fail to be found on loading.  If you're feeling adventurous, you could try building your own kernel and enabling the support that is needed.

[enzol]

Thank you for your answer.

So, without build my own kernel, there is no way to use a EDGE modem with myRIO ?

[tduffy]

enzol,

I did a quick search, but it looks like just about all EDGE/EGPRS/IMT-SC USB-based modems use PPP to communicate.   Without PPP support compiled into the kernel, you're kind of out of luck.  As BradM stated, looks like a kernel module isn't going to work due to a variety of dependencies.  Looks like your best bet may be recompiling the kernel.

Note: The source code to all of the OSI licensed code that is on the cRIO and myRIO devices isn't available for download via a direct link, you much email NI at licensing@ni.com and request it.  More information on this can be found in the FAQ: https://decibel.ni.com/content/docs/DOC-35053 ( search for the word 'licensing' to find the question/answer of interest ).

Another option would be to place some other device in your myRIO design that understands PPP via USB and could translate to another protocol that the myRIO supports natively.  Note that this is a pretty extreme 'hack' just to get around not having PPP support in the kernel.

Hope that helps,

-TD

[BradM]

One thing to keep in mind is that, unfortunately, as things stand now, if you recompile your kernel to have PPP support, there's a good chance that the NI drivers will no longer load (without them being recompiled, that is). This, and the process through which source is requested, are areas that we are looking into improving

[BradM]

I have spoken too soon, I mis-remembered whether or not that we included the support for PPP in the shipping kernel, and it looks like we did. As I recall, the configuration of the pppd config is a sensitive beast, that is somewhat dependent on your hardware and your carrier, so you probably want to run it in "foreground" mode (using "nodetach") to see how it complains, make changes to the config, and retry.