Rolf Kalbermatter

QUOTE(ashwin @ Jan 27 2008, 04:56 AM) Forget the queues for a moment. You want to call those DLL functions in a loop or something and test it's return value or it's returned parameter until it gives you the value to tell you it is ready. Then you call the function to retrieve the data or do whatever else you want to do. There is no way to use LabVIEW queues or such directly with the DLL. Once you have the DLL calls working properly you can of course develop a VI library that could give you a queue based interface. But I do not think that would have real advantages over a more direct VI library approach directly. Rolf Kalbermatter

QUOTE(PeterB @ Jan 27 2008, 06:34 PM) But they execute in a structure that also handles all the normal UI events that WILL switch to the UI thread for sure. And also might contain a timeout case that will also snoop some time for handling. ONe extra point. Queues are very specifically optimized to NOT copy data at all but instead use the reference to the data instead. User events might not be able to use the same optimization in all cases or even at all, especially if you use multiple event structures to receive the same event. Rolf Kalbermatter

QUOTE(ashwin @ Jan 26 2008, 09:32 AM) You can't. For a driver to inform you of something it must implement some kind of event notification. For DLLs there are two possible solutions, they can either allow you to install a callback function that will be called when an event occurres or they can use OS events to inform the caller about such an event. In any case these are things that are not directly translateable into LabVIEW events so you will basically have to write a wrapper DLL that calls your Device DLL with the event notification method that your driver uses and translates it into something more LabVIEW friendly such as a user event or occurrence. C programming knowledge will be required for sure to do that. Rolf Kalbermatter

QUOTE(Yen @ Jan 25 2008, 06:52 AM) Yen you are right here, but there needs to be some extra clarification since a LabVIEW refnum is a memory resource too, and I have trouble to believe that .Net will have any influence on the life time of that refnum itself, even if .Net has a very smart Garbage Collector. It may invalidate (but probably won't since the LabVIEW refnum holds a reference to the .Net object) the .Net resource that was referenced by the refnum, (and possibly though not for sure, the Not A Refnum node may be able to detect that too), but it most likely will not dispose of the LabVIEW refnum before the Top Level hierarchy that created it goes idle. So Your concerns are fully valid and Big Hanks claims are likely to be not the full story with using .Net in LabVIEW. Rolf Kalbermatter

QUOTE(Jim Kring @ Jan 7 2008, 08:18 PM) Well that last link talks about IStorage file format. So this would mean it is basically an OLE structured document format just as the older MS Office file formats. The difficulty about this is of course that the OLE structured document format only defines the container structure but not the actual contents in the streams. It's much like XML without any schemata. I'm not sure if chm is OLE structured document format but if it is, I think the description in that document is a bit limited. It may work most of the time but assuming that it will be always like this is going a bit to far. The actual layout concerning the different OLE streams could be changed by adding additional, non-standard streams to the document and suddenly the fixed offsets are not so fixed anymore. Rolf Kalbermatter

QUOTE(mballa @ Jan 22 2008, 10:31 AM) Hi Dan, welcome too. mbella: It's always so amazing what Google can do for you http://performancemicrowave.com/sql_LV.html' target="_blank">SQL LV Rolf Kalbermatter

QUOTE(Jim Kring @ Jan 21 2008, 09:10 PM) Not very likely for LabVIEW's UI widgets itself. Porting the existing widget code they build themselves since LabVIEW 2.5 on the various platforms to Trolltech would be a complete horror with many bugs, and functionality they simply can't implement on top of Trolltechs QT. It seems to be related to some of the configuration utilities that got added recently. There is a http://forums.ni.com/ni/board/message?board.id=170&message.id=276416&requireLogin=False' target="_blank">thread on the dark side about it, where someone had troubles with it since his external code (Surround SCM) was using a different version of QT that clashed with the one LabVIEW was using. Apparently the Multi-Variable Editor is the whole story why QT is used and that is in essence a DSC feature only. However as that thread shows the QT libraries are loaded into the LabVIEW process independant if the DSC system is used or not. Why they wouldn't write the Multi-Variable Editor as LabVIEW Vi is a bit beyond me though. LabVIEWs widget tools are quite up to par with QTs. Rolf Kalbermatter

QUOTE(sara @ Jan 21 2008, 04:43 PM) How about reading the LabVIEW manuals concerning LabVIEw controls, datatypes and especially strings and arrays? Rolf Kalbermatter

QUOTE(sara @ Jan 21 2008, 02:51 PM) Well you will have to store it somewhere. A poor mans choice would be a tab separated spreadsheet file to start with. Doing it more complicated would be nice but start out with something that you know you can do. Rolf Kalbermatter

QUOTE(tcplomp @ Jan 16 2008, 01:53 PM) This is no problem for the VI server. It can handle multiple client connections in parallel.There are some application properties (private I think) where you can monitor the connections and I think limit or even drop some of them yourself, but normally it can handle multiple connections. As to the original request, I'm afraid there is no way you can retrieve the remote address and remote port from an existing Application Reference. Injecting a VI into the remote side that you can then execute to retrieve the remote sides local parameters would be the only idea that I have. However I don't think any of the VI server stuff allowing to execute VI code that exists as a memory stream will be accessible remotely because of security concerns. So you would have to get that VI on to that computer in some way that requires physical access to it. Rolf Kalbermatter

QUOTE(tcplomp @ Jan 15 2008, 12:10 AM) That is a very good remark. As it seems to me Mikail has some sort of test application. This is in most cases the ideal application to use dynamic execution of the test steps as in some sort of plugin architecture. Also what I suspect is that he maintains the data in a front panel control/indicator or something through locals. If he would use shift registers, Request Deallocation would not have any influence since the shift register needs to maintain its data between executions. On the other hand shift registers allow programmatic clearing whenever desired. This means that for using shift registers which among other modern constructs like queues is the way to store intermediate data, Request Deallocation is getting rather useless. I feel that Request Deallocation makes no sense in 99.99% of the cases for a properly designed application. Rolf Kalbermatter

QUOTE(TiT @ Jan 14 2008, 04:18 AM) They do work but they do not return or modify the actual time in DST and non DST format but the current switch over time to start DST and end it. Rolf Kalbermatter

QUOTE(NateO @ Jan 10 2008, 04:34 PM) While VxWorks is used for the NI-RT targets such as newer Fieldpoint Modules or CRIO controllers I do not think you can just go and install any VxWorks OS and then use that from LabVIEW-RT. The RT OS on those targets definitely has been customized to allow LabVIEW RT to directly work with them. The other option that is more likely to work is the Pharlap OS. NI sells the LabVIEW Real-Time Deployment License for Standard PC's- ETS RTOS which is based on this OS. There you have official support to install a LabVIEW RT supported RTOS on your own computer hardware although there are some specific requirements such as for the network interface. The only other solution I see if you want to use LabVIEW is LabVIEW Embedded. But there you have to customize the environment to interface to the tool chain for your target system, if you dont happen to use a target that is already supported and I'm not aware of an already existing PC104 target. Rolf Kalbermatter

QUOTE(guruthilak@yahoo.com @ Jan 14 2008, 01:29 AM) You can but it is not a magical wand that makes your programs go faster or work better just like that. In fact it is likely it will make them much much slower. Request Deallocation tells LabVIEW to deallocate all memory that is not currently in use. And that will deallocate memory that a VI that is currently idle may just need 1ms later again to do its work so it has to allocate it again instead of being able to reuse it. Request Deallocation only makes sense when you have a VI that uses lots and lots of memory and only runs once or maybe every two weeks in the lifetime of your application. Doing a Request Deallocation right after executaion of that VI may (or may also not) improve the memory consumption of your application. Otherwise this function causes more trouble than it would solve, which is why it isn't very prominently made available. Rolf Kalbermatter

QUOTE(guruthilak@yahoo.com @ Jan 7 2008, 11:16 PM) The only people really knowing about this are in the LabVIEw development team at NI corporate. And no that license is not for sale! You need to have a very strong case and good connections that anyone at NI will even acknowledge that there is something like such a possibility. I would expect maybe three or so Alliance members worldwide being allowed to use that feature. And no we are not one of them, I use the other methods mentioned elsewhere on this forum for the few times I happen to have time to dig deeper into this. Rolf Kalbermatter

QUOTE(BrokenArrow @ Jan 7 2008, 07:49 PM) Vi Analyzer is some LabVIEW versions old now and its analysis might have been correct when it was implemented. LabVIEW does make optimization improvements with every new version. That said Build Array is not a complete no-no. Sometimes there is no way around it or it is in a loop that executes only a few times. But it should always be checked and double checked if you do not want an application that gives you way to much coffee time when it is run. Rolf Kalbermatter

QUOTE(vituning @ Jan 4 2008, 11:45 AM) You can't do that in LabVIEW like that. A Byte array (and a string) in LabVIEW is something very different from a C pointer. When you pass such an element to the Call Library Node and configure the parameter as C pointer, LabVIEW will do the translation for you but inside a cluster is something LabVIEW won't do (and in fact can't do without a configuration dialog that would intimidate anyone but the most diehard C freaks). You would need to treat it as an uInt32 and then do the pointer to array data and vice versa in the LabVIEW diagram with the use of more CallLibraryNodes calling into external functions to copy data in and out. As to this function it is not clear if the caller is supposed to allocated the necessary pointers with the required size or if the function will allocate them. In the first case you would need to call even more external functions to be able to do that, in the second case there would need to be a driver provided function to deallocate those pointers again. All in all a real pain and this particular API is very unfriendly to callers in general! It's even hard to call in C and simply a pain in any other environment. Rolf Kalbermatter

QUOTE(crelf @ Jan 2 2008, 02:35 AM) Very nice Tomi! Congratulations to your insigthful and interesting posts here on LAVA. Looking forward to more of them! Rolf Kalbermatter

QUOTE(Kyuubi™ @ Jan 2 2008, 01:46 AM) How about searching through he examples under Help->Find Examples? Gives you a simple example using the Splitter bar! Rolf Kalbermatter

QUOTE(aart-jan @ Jan 1 2008, 07:57 PM) If you just want to encode the data after it has been acquired entirely the command line tool approach should work. For longer sound acquisition this may not be desirable and in that case I would simply create an interface to one of the existing open source compression libraries such as Lame, through the Call Library Node. But there is one issue with MP3 that OGG probably wouldn't have, and that is the fact that some companies try to squezze money out of every use of MP3 encoding software. So your application while working technically alright may have legal issues. probably not an issue for a home grown hobby application, but certainly a problem for a professional application. I'm not sure about the "run until completion" true problem though. I haven't seen this yet and I do make use of the system exec regularly. Rolf Kalbermatter

QUOTE(tcplomp @ Dec 29 2007, 01:09 PM) It's complete. ASCII doesn't define more than that. The rest are extended characters that depend on the currently set local, the font used etc, etc. Rolf Kalbermatter

QUOTE(psi @ Dec 29 2007, 05:47 PM) Hmm, you will have to buy a runtime license per system, and that is about 500 Euro in single quantities. Interesting yes, not expensive only if you are not planning to make an embedded device, although I'm sure you can negotiate volume license prices. QUOTE LabVIEW Real-Time supports not only NI hardware device. LabVIEW Real-Time can supports Third Party Device. Can I Use a Third-Party Device with LabVIEW Real-Time (RT)? Third-Party Compatibilit Configuring the NI Real-Time Environment and NI-VISA toRecognize a Third Party Device Porting a Windows Device Driver to the NI Real-Time Platform Yes for desktop PCs but not for arbitrary embedded development systems. For some reasons I was assuming that embedded was the route the OP wanted to go. Rolf Kalbermatter

QUOTE(psi @ Dec 28 2007, 05:51 PM) But LabVIEW realtime only supports NI hardware targets (some of them use Pharlap OS and other newer ones with PPC CPU use VxWorks) and somewhat specific x86 hardware with Pharlap (ETS). If the OP wants to use NI hardware targets or can live with a more or less standard PC hardware platform then LabVIEW realtime of course would be best. Rolf Kalbermatter

QUOTE(Dr. Dmitrij Volkov @ Dec 28 2007, 09:07 AM) The equivalent of DLLs in VxWorks are .out files. They are basically shared libraries created with either the VxWorks development system or the free GCC compiler. I've only created one of them so far using the freely downloadable GCC version for VxWorks to create a shared library for NI's newer real time controllers. But I'm not sure what you are trying to do here. LabVIEW for VxWorks is only available for the NI realtime target systems. For your own VxWorks based systems you would have to go the LabVIEW Embedded route. Not very cheap but maybe you are doing that already. Rolf Kalbermatter

QUOTE(Yen @ Dec 21 2007, 07:59 AM) A well Heinlein :thumbup: . Certainly an interesting author. Although I wouldn't share every of his visions and he seemed to have some militant ideas at time, he also had a very impressive way to describe environments and social interaction that were strange and bewildering, while at the same time still somehow believable. My first contact with him was by stumbling more by accident over "Stranger in a Strange Land" and it took me quite some time and writing an essay over this book for school to see the finer points of this book. And it changed the way I looked at many things remarkebly. Rolf Kalbermatter