ShaunR

I had not considered multi-dimentional arrays. JSON doesn’t have a multi-dimentional array type, but we could just have arrays of arrays. I will look into supporting it. Thanks.

N dim arrays don't have a "type" but they are represented

e.g. Array:[[1,2,3,4,5],[1,2,3,4,5]]

This causes us a problem in the way we convert to type from a variant (recursion works against us due to the fact that it is not a recursive function. it is iterative). If we were just dealing with strings, then it would be fairly straight forward.

For example. Using the "Set From Variant" in a for loop works fine for 2D arrays. But for 3D arrays it will give incorrect results (try with the "Example Creation of JSON string.vi"-bug).

One way forward is to detect the number of dims and have a different "Set JSON Array.vi" for each (max 4 dims?). But this is ugly (POOP to the rescue?).

Without

I don't really have an issue on this (however some direct attribution/link would be nice).

However it brings up a strange angle in the whole NI.COM license discussion:

The code is licensed under the BSD (while I don't specify it, attribution should be given).

The ni.com license says 'Upload it and it belongs to us' (Shaun will love that wording)

So uploading / sharing the code under the BSD license on the internet is OK, UNLESS you post it to ni.com. (other sites might be banned as well).

Concluding the user is not breaking the BSD license, (if he attributes), but is breaking the ni.com EULA.

Ton

I could argue many aspects of that. The windows API is a much stricter license however (Creative Commons Non-Commercial Share-Alike).

More importantly. In the case of the code that's taken from the windows API, an attempt has obviously been made to pass it off as original work (plagiarism in academic circles) otherwise, why change the icons, the distribution format, remove the attribution notices in the revision info and license file. That's just "not cricket" and should annoy you in terms of your code as much as it does me. I'm not saying that the person that posted it on NI.com did this (although they have opened themselves to the issue). They could have innocently picked it up from somewhere else. It does however highlight the importance of licensing and the validation. if not commercial gain, that some seek from the efforts of others.

Maybe a MOD can move these comments to the licensing thread so as not to gum up this support thread?

His icons are nicer than yours ;P

Well. in my defence. They were originally written in about 1997 before all the new fangled icon bitmap editing. When a customer complains about icons rather than bugs; maybe then I'll change them

From the VI description of the first random file I opened.

© Ton Plomp, 2011

THIS SOFTWARE IS PROVIDED AS IS, AND ANY WARRANTY IS REJECTED

Indeed. He has been a busy ;little squirrel.

This drives info is taken from my windows API (windows_api_Drives.llb).

Do you see the same thing if you just put a linear sequence of numbers into the sine primitive?

I ran the updater on that machine (had to drag it over to the offices to get an internet connection), updated everything and the problem seems to have gone away. It solved the problem, but I can't tell you which patch/update/package was the one that fixed it and I can't now replicate the problem-just needed to get it working.

There doesn't seem to be a problem in LabVIEW 2012 (lvanlys.dll 12.0.0.3) or LabVIEW 2011 (lvanlys.dll 11.0.1.2), checked for both 32-bit and 64-bit. This is on a machine with only those versions installed.

Yup. I think lvanlys.dll is installed with the Device Drivers CD (the machine also has 2012, but the lvanlys.dll seems to be from 2010). That would also explain why it affects all versions.

Just downloading the latest Device Drivers installer to see if that cures it.

I've been troubleshooting some code to find out why I was getting corruption in waveforms when using the Pt-by-Pt VIs.

It seems that it it a problem with the latest lvanlys.dll in the run-time since older installations do not exhibit the problem. It affects all labview versions (from 2009 onwards) and both 32 bit and 64 bit.

This is the result from an installation using lvanlys.dll version 9.1.0.428

And here from an installation using lvanlys.dll version 10.0.1.428

The problem is that the output is switching sign at arbitrary intervals as can be seen in the following table:

Formula nodes are for c and matlab programmers that can't get their head around LabVIEW (or don't want to learn it).

It's well known that it is a lot slower than native LV and it's a bit like the "Sequence Frame" in that it is generally avoided. I would guess there are optimisations that LabVIEW is unable to do if using the formula node which are reliant on the G language semantics (in-placeness?).

You could always do it the easy way and just extract the bytes to determine type and link them to a case structure for decoding.

I triedd with as PNG image and transparent background, but at the output of the rotation VI the background is black...

there something wrong in my actions?

Max

example.vi

Nope. Nothing wrong.

The ""unflatten pixmap" strips the alpha-channel and coerces to 24 bit.

I suggest you use the rather excellent "BitMan" package in the CR.

Why are my runtime exe menus jibberish?

Uninstalling the latest version (LVRTE2011SP1f1) here and reinstalling the older version (LVRTE2011f3) here fixed it.

I think the confusion came from trying to have the same architecture as the firmware (multiple zones all reading the same message off the CAN bus) but this is not possible in a simulated environment on the PC.

Actually it is quite possible. Use Events and all zones register and filter for messages. This is directly analogous to what the CAN bus is doing.

Once somebody understands the "ideal" way to implement something--and more importantly why it is "ideal"--then they are in a better position to make decisions on when it is okay to use less-than-ideal implementations. But to get to that level of understanding requires somebody pointing out the flaws and consequences of the implementation they're using. IMO why is the most important question humanity has ever asked.

That's what training courses and seminars are for. Forums (to me) are for the "I've got this problem with this code,, anyone know how to fix it?" questions and general, unstructured "discussions". Therefore I don't see them as an ideal or even particularly good platform for "training". Most people IMHO post and want/need an answer in a day or so. Understanding architectures takes longer than that and doesn't solve their immediate problem.

So using your analogy. They already have the bloody stump. I usually give them a band-aid and tell them how not to lose the other one

It also requires that you know the type ahead of time to drop the correct terminal. Which of course is the point of the "run time" preservation in the suggestion (yes I know there's nothing "run time" about it, but we are drawing an analogy).

You also need to know the type ahead of time with the others as well (supply a control to define the type). I would prefer it just coerces to the type of the indicator that I hang off of it which in fact is more useful than the "To Data" and James would get his function without having to define the type input. It (i think) should behave like a polymorphic VI but we don't have to write all the cases.

Until that happens. I'm still using strings and variants (to me) are still the feature that never was..

Can I also reiterate my long standing peeve about not being able to create "native" polymorphic controls/indicators. X controls is another "half" solution.

I’ve proposed it on the Idea Exchange.

I still think this is a "half" solution. With variants, we should just be able to wire an output to an indicator and it should just do it without explicit conversion.

Users posting on a forum tend to have been trying for a while to get round a specific problem or lack of understanding. Muddying the waters with architecture (when not asked for) tends to just confuse and frustrate. I'm reminded of what a teacher once said to me for exam technique. Answer the the question, not what you think they are asking.

I tend to solve the immediate problem (usually with an example) then suggest improvements. However. Rolf has a huge amount of experience in umpteen programming languages as well as solving comms problems on a day-to-day basis so his one-liner is second nature.

It helps when they post an example as then you can tell their level of expertise. If they have roughly hacked an example shipped with LabVIEW and it "sort of works". They may have spent all day trying to get the last bit sorted. This generally means that they if you start spouting about OOP and Actor frameworks, then they will probably just give up as "LabVIEW is too hard to do simple things".

That just creates a single point of failure. Something I cannot do in this system as the cost of it failing is expensive. I can live with one server going down or one client, but not something central to everything.

Depends how many dispatchers you have. If you have a single dispatcher (centralised server like a DNS server) then yes. If you have a dispatcher on every machine (like apache), then no-as long as you have reduntant processes elsewhere. The usual topology I use is to have a machine with, say, 5 processes and replicate that for failover. If the machine goes down then you just point to the other machine(s). That's the way the web works

But haven't we discussed this before?

The end goal is a system where there are N servers and N clients. Each client can connect to N servers at the same time. Servers support N connections from clients simultaneously Servers 'push' data changes to the clients. Clients send commands to servers to control them. The data is mostly small but there are some circumstances where it could be around 1M. But that would not be continuous. Only once a minute or less. Most of the time the messages will contain a few k of data at most.

Clients will drop off from time to time and the servers will automatically detect this and stop sending to them.

Clients will know the machine names of the servers and will contact them to start a connection.

I really wish the VI Server method was feasible. It is by far the simplest and cleanest.

I will look at those examples. thanks,

-John

Yup. I meant the example to show dynamically launching of TCP processes (there are hidden "handlers" which are dynamically launched).

I don't see any reason why it should be an issue. Launching dynamic VIs means you can run them in separate threads and/or execution systems from the launching process so although your dispatcher might be in the UI thread, the spawned processes need not be.

Do you have an example? Seems I would have to create a listener on the receiver side for every 'potential' sender. Since the receiver does not know who the senders might be, I can't think of how to do that.

The LabVIEW UI has sucked for quite a long time now, but If your going to go for HTML and CSS you might as well take it completely out of LabVIEW and make it platform independent.

Unfortunately, When it comes to artistic talent, I wasn't even in the building when they were handing it out So as much as I complain about the LV UI, I can't really do any better. The guys/gals that make those interfaces for the coding challenges just blow me away.

Any UI in CSS, SVG and HTML that I do takes weeks and looks, at best, mediocre.

The server had a nervous breakdown because I got to the number 2 spot

The proble. With this will be identifying the object in the first place, the hand, and it staying consistent enough.

This can be alleviated by using a camera with a shallow depth of field so that the hand is in sharp focus but a few inches back is totally out of focus. He will not be able to do that with a laptop cam however, but he might get away with a webcam with a manual focus ring if he is far enough away.

Hi,

I need to stream 40 MBps to disk, .tdms, on a NI PXIe-8133, quad i7 1.73 GHz from 10 DIO cards. I understand that 40 MBps is roughly the max of what the SATA drive will do. I'm getting at least 30 MBps. Is the 40 MBps limit assumption good?

I think I should have a dedicated drive for the data instead of streaming to the controller drive. RAID is surely overkill. Has anyone connected an external drive to a NI controller with the ExpressCard slot? Any other ideas? I think my producer consumer code is ok.

cc

Depends on the drive.

SATA 1.5 theoritical max is 150 MB/s, SATA 2 300MB/s and SATA 3 is 600MB/s. I have a NAS box at home that easily does a sustained 60MB/sec over a 1Gb connection (with Jumbo frames).

NI PXI racks have pretty crappy hard drives as standard I would benchmark it with these

http://zone.ni.com/devzone/cda/epd/p/id/5348

.....then buy a decent one

Are the HTTPS VIs that are shipped with LabVIEW 2010 and later not of any use?