Linux preference

[Jorge_Amaral]

Hello to all

I'm labview developer for some years. But always on windows. I started to use opensuse 12.2 this week to create a simple application with a serial communication. This was not easy and I couldn't communicate with the device using USB.

I tried to get support from Ni but they seem to be not very expert on this.

So, can you please point to a good direction by recommending me the best Linux distribution for labview with visa application.

Thanks in advance,

Jorge Amaral

[BradM]

Jorge, welcome!

If you're speaking of creating a serial app using LabVIEW for Linux and VISA using a USB-to-RS232 device, this is a known issue that has also popped up with new Linux RT cRIO controllers. It is currently being evaluated to be fixed but in the meantime you can resolve this in one of two ways:

1) Use built-in RS232 serial ports on your computer that is running LV.

If this is not an option (e.g. you are using a laptop that does not have a serial port), then

2) Write a wrapper library in C/C++ to shuttle data to/from LV

Yes, I know that the latter option is not a great one, but until the issue is resolved in how VISA discovers USB serial ports on Linux, that's your best solution.

BradM

[Jorge_Amaral]

Hello Brad! Thanks for your answer.

What do you think about opensuse 12.2? Is it the best distribution for me?

Since I don't know any Linux I can select the one that people think that is best.

My first app is one that connects with arduino (by serial port by preference) and controls some hardware. And I was able to:

1. Receive the bytes sent by the arduino using USB and arduino serial monitor

2. I was not able to receive the same byte using he serial port. With all the permissions set (a least the ones that I saw in my google search.

3. In labview, USB are not listed and the serial opens but can't also read.

My idea: serial port has a problem. Let's try another computer.

But installing is not straight forward. And now I have an error start my labview app (can't remember the error but includes "mAybe run updatedriver" - I'm not in the office).

At this point we decided to try another Linux. And this will be centos 6. Is this the best for me (a guy that is new in this world).

Thanks again

[Randy_H]

Centos 6 should be OK, but know that NI officially supports RHEL 6 and Scientific Linux 6. SL6 and Centos6 are derived from the same source so you should not have any major issues.

The message about running "updateDriver" is something that implies that some part of the VISA driver did not install properly On SuSE, there are some extra kernel configuration steps that have to be done before the NI drivers will load. RHEL/SL/Centos does not have this issue (at least that I can remember).

[Jorge_Amaral]

Good morning Brad! Thanks for your help. I will give it a try.

THANKS

[BradM]

Randy_H knows what he's talking about, I would trust his oppinion. I have the tainted view of already knowing how to work with different linux distributions.

If it's complaining about running updateNIDrivers, something did not install correctly with regards to the drivers. Again, I defer to Randy_H.

Also, as I noted, even if VISA is installed correctly, I don't think that the issue with detecting a USB serial connection as a valid serial port has been resolved yet.

[Jorge_Amaral]

Thanks BradM!

I've already installed Centos 6.5 and I already encountered my first problem. It gives error installing visa 5.4. And If I try to right click and unpack the file .tar.gz, returns error eof not found (something like this).

Do I have to do something before installing it?

PS: I'm really really new to linux.

[BradM]

Jorge,

That sounds like there may be an issue with the .tar.gz (commonly called a "tar ball", a type of archive file like a .zip file) where it may be corrupted. Right now, I am having difficulty downloading VISA to test it out on my Linux machine (the ni.com site seems to be slow)

Also, in the meantime, you can work around the issue for using a USB port with the instructions listed here:

http://digital.ni.com/public.nsf/allkb/0DA74DF33C4764DC8625717A005F1F09?OpenDocument

[Jorge_Amaral]

Hello Brad,

I Already saw that workaround but I have a problem. My Visa instalation doesn't creates the application "visaConf" utility. I already questioned NI Support about that but he never answers me that (don't know why). But I found in the same folder the visaconf.ini (or visaconfig.ini) and edit so that the link is created. But with no success till now.

Currently I'm doind two tests:

1. Install the centos 6.5 32 bits ( i think that I installed 64 bits the last time);

2. Install opensuse 11.2 in another machine

I will reply with the results after.

Thannnnnnnnks!

[Jorge_Amaral]

Results:

1. Centos 6.5: can’t install rpm and says “digest mismatch”. One solution suggested for that is to disable “prelink”. But returns the same error.

2. linux 11.3: can’t see “visaconf” utility after installing visa 5.1.

Is it possible to give me a winning combination of suse and visa that works with less problems?

Br,

Jorge Amaral