topic Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected in LabVIEW Channel Wires

LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

siadajpan — Thu, 01 Sep 2016 14:22:32 GMT

I've already posted this question here: http://forums.ni.com/t5/LabVIEW/LV-2016-LabVIEW-could-not-create-the-requested-channel-endpoint/m-p/3341837#M981451

When creating channel writer, there was a pop up Select Channel Endpoint, but regardless of selected option, there is a window saying "LabVIEW could not create the requested channel endpoint", error code: 8 file permission error

NI-488: DMA hardware error detected.

I have file permission error for some file, which file is it?

Thanks for repond

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

AristosQueue (NI) — Thu, 01 Sep 2016 15:05:10 GMT

Is your LabVIEW Data directory writeable?

On Windows, that directory is

C:\Users\<username>\Documents\LabVIEW Data\

I don't remember Linux or Mac off the top of my head.

That's the directory where channel instances get instantiated.

C:\Users\<username>\Documents\LabVIEW Data\2016(64-bit)\ExtraVILib\ChannelInstances\

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

sth — Thu, 01 Sep 2016 16:18:13 GMT

Mac

/Users/<login name>/Documents/LabVIEW Data

as expected.

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

siadajpan — Thu, 01 Sep 2016 16:57:45 GMT

Thanks for this localisation. I've tried to deselect the read only from this folder, but it didn't solve the issue.

What I was trying to do is to set True constant to stream channel writer. In the folder:

...\LabVIEW Data\2016(64-bit)\ExtraVILib\ChannelInstances

there is a folder Stream-bool with 20 items (vi's and Stream Data class), but when I've tried to open one of these, LabVIEW couldn't find some other vi's.

I'm trying to reinstall LV2016, maybe it will solve the issue

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

AristosQueue (NI) — Thu, 01 Sep 2016 19:13:02 GMT

> I've tried to deselect the read only from this folder,

Was it actually read-only?

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

siadajpan — Thu, 01 Sep 2016 19:54:35 GMT

Windows is setting everything in my C:/ to read only, I've unticked read-only it in LabVIEW Data, and check if I can rename some files. I could, so I've done it well

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

AristosQueue (NI) — Thu, 01 Sep 2016 20:31:34 GMT

Weird. So... does creating a channel work for you now?

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

Bob_Schor — Thu, 01 Sep 2016 22:23:09 GMT

Where are your User files, like My Documents? By default, in Windows 7, 8, and 10, they are in C:\Users\<Your User Name>\Documents. This folder has to be read/write by you -- if you are logged in as someone else, you won't have Write permission (and may not have Read permission either) to it.

The folder that LabVIEW uses for the Channel Wires is in the LabVIEW Data Folder, by default in \Documents\LabVIEW Data, so it should (and must be writable by the logged-in User).

It sounds like something is definitely screwy with your Windows system (or someone, a Virus, perhaps?, is messing with you). I don't think this is the fault of LabVIEW or Channel Wires ...

Bob Schor

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

Bob_Schor — Thu, 01 Sep 2016 22:27:05 GMT

An idea just occurred to me. By any chance, did you change the location of the Default Data Directory that LabVIEW uses? Open LabVIEW, go to Tools, Options, Paths, and look at Default Data Directory. It should be something like C:\Users\<Your Name>\Documents\LabVIEW Data. If you've put it somewhere else, especially if you have moved it out of your Profile and on to the C: drive, it might become Read-Only ...

Bob Schor

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

siadajpan — Tue, 06 Sep 2016 12:42:01 GMT

Success!

I've just discovered that on my work's PC, I've got two Documents folder. One is the local one in C:/ drive, the other one (default for everything) is on the network drive (UK-PRIMARY\UsersHome\<myname>\LabVIEW Data)

I've changed the Data folder as you've described.

After changing this folder, and copied everything that was in LabVIEW Data Folder to the new location (C:\Users\<myname>\Documents\LabVIEW Data), and making sure, that I have all the permissions to this folder, I've done my previous creating channel writer, and it worked this time.

Thanks for the help!

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

Thoric — Tue, 06 Sep 2016 12:52:31 GMT

Nevertheless, a networked Data folder would need much the same permissions to allow you and Windows applications to use it the same as it might a local Data folder.

Why is LabVIEW unable to use the LabVIEW Data folder when it's networked?

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

AristosQueue (NI) — Tue, 06 Sep 2016 15:25:41 GMT

I'm glad you got things untangled.

I'm not sure if I can improve this much ... trying to explain in an error dialog all the things that could be wrong with writing to a path is pretty extensive.

I can at least look into getting the path into the error message.

Re: LabVIEW could not create the requested channel endpoint File permission error; NI-488: DMA hardware error detected

siadajpan — Tue, 06 Sep 2016 16:23:54 GMT

Yeah, this was my first question: what path is it that LabVIEW has problems writing to?

From there, it's either permission problem or this whatever happened to me.

Thanks!