CAN Frame to channel conversion using CVI

[johnswan]

Hi,

I am using USB-8473 can bus modules in a project.  I would like to display the channel data by using the Frame to Channel conversion library.  Is there a version that can be used with CVI?  I am using CVI 9.1

Thanks

John

[Anna_K.]

Hello John,

Unfortunately, an equivalent Library does not exist in CVI.

With that said, you may be able to dig into the LabVIEW VI's of the Frame Channel Conversion Library and pull the function prototypes from the Call Library Function Node on the block diagram of each one. With this information, you could call the functions from the dll (usually located here: C:\Program Files\National Instruments\NI-CAN\CAN Frame Channel Conversion Library 1.0.2\Drivers) from within C.

I hope this helps,

Anna K.

[johnswan]

Anna,

Is there a reason that National Instruments doesn't give the support to the CVI customer base that it gives to the LabView customers?

I would think that the support answer would not be that I should "dig through" the VI to figure out what is going on...This is not very helpful.

Regards

John

[Anna_K.]

Hello John,

I do see what you mean, the VIs actually just call into a C dll. I dowloaded to the Library after reading your post and opened up the VIs. It looks like each is just a small wrapper around Call library funciton node. It is definately silly that the VIs are so well documented but not the functions of the dll itself. Based on browsing a few of these VIs, it would be pretty easy to write the wrapping code in C and call all the same functions of frchconvlib.dll. 

I will look into whether this library was written by a third party or NI, and if its NI property I would like to expose the dll itself to users like yourself. 

I do apologize that this is the only current solution. I will let you know what I find out.

This kind of feedback it important to receive, so thank you for voicing you concern.

Best,

Anna K.

[johnswan]

Anna

Thank you for the prompt reply.  I do appreciate you looking into supporting the CVI users.

Thank you

John

[HoussamAz]

Hello, 

I have the same problem in 2018 ... 

But I need to convert channels to CAN frame. 

Any thing is done for CVI since 2010 ? 

[Hooovahh]

I'm not a CVI user but it looks like XNet is supported on CVI, and XNet has a conversion session.  In LabVIEW it is pretty easy to use this conversion session to go from frames to signals and signals to frames.  I thought I could do better on the performance front so I ended re-writing the conversion session to be in pure G.  I know it can't be brought into CVI but you could look at the source and understand how the conversion work, and see the XNet calls to get scaling information.

[HoussamAz]

Thank you.

Yes, XNet is supported on CVI.

The problem is that under CVI we don't have all XNET functions/tools like LabVIEW. It's really disappointing. 

[GPIB_Guru]

What specifically is missing in CVI?

[HoussamAz]

A way to get bytes of CAN frame (as written in the bus)  using only the DBC file and data user values.