Rolf Kalbermatter

QUOTE(Ben @ Sep 27 2007, 07:53 AM) Long ago I did look into this also in combination to interface to external script servers like Python for instance. One idea I came up is to use the LabVIEW TCP/IP VI server interface directly (instead of going through it's Active X interface which would limit the solution to Windows LabVIEW hosts only). I could access this interface through direct TCP/IP sockets in LabVIEW 6.1 but eventually run into some problems to access the Call by Reference interface (nothing that couldn't be overcome but the flattening of the typedescriptor and the different parameters is a real headache to get right and requires a lot of inside research into the LabVIEW datatype storage model (almost fully documented in an older App Note). I eventually stopped development on this because of several reasons. - My Library was for ease of testing and debugging written in LabVIEW. Not very useful really considering that you can much more easily use VI Server directly and converting this interface to another language like C, Python, etc would still be quite an undertaking. - NI obviously never documented that protocol for some reasons. One of them is that they change it between LabVIEW versions albeit not extremely. But the introduction of the 32bit safe typedescriptors in LabVIEW 8 certainly must have had a profound impact on that protocol although I never looked into that. Support of the entire (private) LabVIEW object hierarchy through this interface in LabVIEW 7 should probably also have made some impact here. In general I concluded this interface to have great potential but its undocumented nature and version dependant changes make it basically unsuitable to rely upon for any serious project. And for just some fiddling around it is way to much work to develop and maintain such a solution in any language I could imagine. But it would be quite feasable to create a LabVIEW DLL/shared lib that wraps the important VI Server methods and functions into exported functions and access that from any host that is capable to call into shared libraries. You would have one DLL/shared lib per platform you want to access LabVIEW from but since VI server is network TCP/IP based that would not have to be the machine that is running the actual LabVIEW target VI. Rolf Kalbermatter

QUOTE(Ben @ Sep 27 2007, 03:13 PM) I used this feature in older LabVIEW versions exactly to detect crosslinking! It allowed to see if a project was referencing somehow VIs outside of the project file hierarchy (and vi.lib, user.lib). Any such VIs I usually squashed immediately to avoid later problems with cross linked VIs referencing VIs from other projects (and even worse: other LabVIEW versions). Unfortunately LabVIEW 8.0/8.2 lost that capability and I didn't get around to try 8.5 yet for any real project. Rolf Kalbermatter

QUOTE(yen @ Sep 24 2007, 01:59 PM) Actually it seems not just to be the spam folder. I recently had to reset my password and did it three times before a mail showed up. And yes I did check the spam folder and yes I did wait about 10 minutes and even longer before reattempting. Rolf Kalbermatter

QUOTE(jbrohan @ Sep 23 2007, 09:10 AM) The problem with speech recognition is that it is a failry complicated technique to get to work in any useful way. I only played briefly with it in other applications, without trying to import it into LabVIEW and it did not feel up to what I would expect from such a tool. It is simply rather complicated to configure and train it appropriately since human perception of speech seems to be such an involved process and as probably anyone who knows more than one language can attest, is also very much depending on the environmental influences where the language is one parameter of it. There has been work in speech recognition for more than two decades now with speech recognition technology already available in the Windows 3.1 area and still it hasn't made it to a meaningful means of human interaction with the computer, not to talk about replacing human interface devices like a mouse or keyboard at all. This has been partly because of processing power and memory usage but that can't be the only problem, when you consider that computers have now already 1000 times as much memory as was common 15 years ago and the CPUs run at about 50 times the speed of then and are even more powerful, not to mention the availibility of multicore and multi CPU systems. Not having looked at the MS Speech recognition API in a long time I can't really say much about it but it has been already complicated years ago and probably got even more possibilities and features since then. Rolf Kalbermatter

QUOTE(siva @ Sep 20 2007, 03:33 AM) SVN really works the same. But the OP request was explicit intermediate commits to the server while away from the network, and here CVS will fail exactly the same as SVN. Only solution I see is to keep the CVS server on the local machine too and put it's repositry on an external harddrive or maybe make a regular backup copy of the entire local repository to some other location. I know that that will work with SVN since a repository is there completely self contained without any external information that could get lost when doing a simple file backup. Rolf Kalbermatter

QUOTE(manic @ Sep 19 2007, 03:39 AM) If I would be tasked with that my reaction would be simple. Don't even try to redesign it! It will cost at least double the time than doing it from scratch and still not be as clean and performent as it should be. Rolf Kalbermatter

QUOTE(Gabi1 @ Sep 19 2007, 04:04 PM) As Aristos already mentioned the extra memory used for a skalar notifier won't really kill your memory at all. The occurrences on the other hand are not producer/consumer oriented and while multiple places can wait on the same occurrence their mechanisme is not in such a way that you could easily do the opposite at all. On the other hand polling an occurrence with a small timeout, while not optimal, will not kill your CPU performance either. Rolf Kalbermatter

QUOTE(karthik @ Sep 19 2007, 02:08 AM) I would think Property Nodes to be the magical solution here. Rolf Kalbermatter

QUOTE(Louis Manfredi @ Sep 18 2007, 11:09 AM) Well, such is life. Most things I found by accident, searching actively for something or through user groups/mouth of word/LAVA/Info-LabVIEW etc. and when then looking for them they were eventually somewhere in the printed or online docs, but it is simply to much material to read through completely. I have long ago resorted to work with what I know and try to learn new things by various opportunities and simply not let myself be bothered that there are still many golden eggs out there that I do not know about. If I would have a photographic memory I would simply scan all the documents in a matter of flipping through them and rely on that, but alas, I'll have to do with what I can. Rolf Kalbermatter

QUOTE(Cherian @ Sep 12 2007, 01:58 PM) Wow, you mean you wrote a driver for the FPGA board to communicate with it from within LabVIEW? In that case I would assume you know more about how this could be done, than anyone else here on LAVA possibly could know. And probably also almost anyone else except those that work for NI and developed the FPGA product and maybe a system integrator or two under NDA. Rolf Kalbermatter

QUOTE(tharrenos @ Sep 16 2007, 11:18 AM) As far as LabVIEW is concerned there won't be any problem. WiFi cleanly integrates into the OS networking stack and as such just looks like any other Ethernet hardware interface to LabVIEW, meaning LabVIEW has absolutely no idea that the packets would go over a twisted pair, glasfiber, dial-up modem, or WiFi network. The central heating part might be a bit more troublesome. You will need to have some hardware that can control the heating and at the same time has a WiFi interface too. As embedded device which would be interesting only for high production numbers that would require some engineering. If you just put a normal (small size) PC beside and run a LabVIEW executable on that too the necessary engineering would be quite limited. Rolf Kalbermatter

QUOTE(Louis Manfredi @ Sep 13 2007, 01:21 PM) Yes upgrade notes would not have worked. They are both in LabVIEW as long as I can remember, which is about version 2.5 or maybe the parse enum wasn't in there but at least 3.0. Possibly 2.2 for Mac only, had it already too. Rolf Kalbermatter

QUOTE(pjsaczek @ Sep 12 2007, 04:47 AM) As indicated already, if you talk to a serial device always add explicitedly the end of message character for that device to the command or if you want to be more dependant on a specific VISA feature set the "Serial Settings->End Mode for Writes" property for that VISA session to "End Char" and make sure you also set the "Serial Settings->End Mode for Reads" property and the "Message Based Settings->Termination Character" property accordingly as well as the "Message Based Settings->Termination Character Enable" to True. As already said it could have problems with older VISA versions (really old) and I find it better to explicitedly append the correct termination character myself to each message. Also note that since about VISA 3.0 or so the default for serial VISA sessions for "Serial Settings->End Mode for Reads" is already "End Char" and the "Message Based Settings->Termination Character" property is set to the <CR> ASCI character as well as the "Message Based Settings->Termination Character Enable" is set to true. However "Serial Settings->End Mode for Writes" property is set to "None" for quite good reasons as it does modify what one sends out and that can be very bad in certain situations. LabVIEW as general purpose programming environment shouldn't do that for you automatically since there are many somewhat more esoteric devices out there that use another termination character or mode then appending a <CR> character or <LF><CR> character sequence. Rolf Kalbermatter

QUOTE(pjsaczek @ Sep 10 2007, 10:52 AM) No LabVIEW is not adding anything to the strings on its own and I would be really mad if it would. However if you use VISA in a more recent version (let's say less than 5 years old or so) you can configure it to do that for a serial session automatically for you. But personally I find that not such a good idea. I prefer to code each command in such a way to append the correct end of string indication explicitedly. Rolf Kalbermatter

QUOTE(jed @ Sep 11 2007, 04:26 PM) The Windows message queue example is not really meant to hook directly into the queue but only monitor it. In order to hook into that event you would have to modify the C source code of that example to do that specifically. Not to difficult but without some good C knowledge not advisable. Another way might be that newer LabVIEW versions will send a filter event in the event handling structure "Application Instance Close?" which you can use to disallow shutting down the app. Not sure if it will disallow shutting down the session directly though. But it should be enough to detect that there might be a shutdown in progress and allow you to execute the command Adam mentioned to abort that. Rolf Kalbermatter

QUOTE(dsaunders @ Sep 11 2007, 03:09 PM) The private property is somewhat a pain to use as it is really a number of informations you would need to check. First the connecter pane layout itself which is just a magic number for one of the patterns you can choose. Then the array of connections with an arbitrary number to identify the position in the connector pane it is connected too and last but not least the datatype of each connection which is a binary type descriptor and can't just be compared byte for byte but needs to be verfied on a logical level since different binary representation do not necessarily mean different data types. Not sure I would want to spend that much time for this! Another possibility and LabVIEW uses that a lot for its plugins is to use the Set Control Value method and then simply run the plugin VI. Makes the connector pane completely independant of the calling information. You just need the correctly named controls on the front panel. Using an occurrence (or notifier etc.) you can wait in the caller for the VI to signal its termination or simply poll its status to be not running anymore. Rolf Kalbermatter

QUOTE(chrisdavis @ Sep 11 2007, 08:45 PM) My best bet is .Net although I think the WinAPI will also give you this information on a somewhat lower level and probably not exactly trivial to access. Possibly LabVIEW has some private hooks itself. Would make sense to have this info in LabVIEW somehow to make it platform independant. Rolf Kalbermatter

QUOTE(Techie @ Sep 9 2007, 10:04 PM) All comments so far have been valid and right. One other thing, creating controls while in principle possible requires the use of so called scripting, a feature that has not been released by NI and made difficult to access too. Also you can not do it on a VI that is running, so for most user applications it is meaningless as you usually want to do such stuff from the VI itself. LabVIEW can not make any modifications to a VI that is running if these changes would modify the diagram in any way and dropping a control on a front panel does modify the diagram. That is also a limitation of the compiling nature of LabVIEW. Rolf Kalbermatter

QUOTE(brianafischer @ Sep 8 2007, 01:50 PM) What version of LabVIEW are you using? LabVIEW since at least version 7 is fully multi monitor aware and moves windows so that some part of it's window is always visible although it does not center them in the primary screen which I would find to intrusive anyhow. Making an application open its windows always in the secondary screen independant of its location is defintely a very esotoric requirement. Personally I find it rather disturbing to have to look right or left of the main screen depending on the setup. It's already hairy enough to switch between single monitor and multiple monitor use. But I know many applications that will open their window always in the last saved monitor location independant if that monitor is present or not and I really find that an annoying behaviour, especially if they replace the default system menu too, so that you can't even move it from the task bar with the cursor keys. And upgrading to LabVIEW 8.5 could help you a lot. There you can configure per front panel on which screen it should be displayed and LabVIEW will honor that if that monitor is present. But i think this is mostly a runtime feature. Not sure it will have the desired effect on the windows in edit mode and definitely not for the diagram windows. Rolf Kalbermatter

QUOTE(yen @ Sep 8 2007, 02:22 PM) In order to be able to connect to a LabVIEW application over AcitveX it also must have been build with that option enabled. I personally always make sure that option is disabled for various reasons, including safety. Rolf Kalbermatter

QUOTE(yen @ Sep 5 2007, 01:36 PM) Just because there is a Basic development environment for this target does not mean that there couldn't be a (Gnu based) C toolchain for it too. Rolf Kalbermatter

QUOTE(tcplomp @ Sep 7 2007, 02:38 PM) And just to show what the pre LabVIEW 8.5 version of this code would look like: http://forums.lavag.org/index.php?act=attach&type=post&id=6885''>http://forums.lavag.org/index.php?act=attach&type=post&id=6885'>http://forums.lavag.org/index.php?act=attach&type=post&id=6885 Forget about the unwired loop termination! ;-) That is not the point here. And if anyone wonders why one would write a VI in such a way. It is called pipelined execution and has advantages on multi core, or multi CPU machines as LabVIEW will simply distribute the different blocks onto different CPUs/cores if that is possible at all. On single core systems it has no real disadvantage in terms of execution speed but this construct of course takes a memory hit because of the shift registers that store actually double the data between iterations than what a linear execution would need. Rolf Kalbermatter

QUOTE(Jim Kring @ Sep 7 2007, 10:22 AM) Just learned that yesterday at the local LabVIEW day here in the Netherlands, presented by Jeff Washington. His example had a loop but was about pipelined execution and boy I can tell you that although I'm excited about this feature, it does need getting used too. Basically with this node you sort of have to forget a few things about data flow and wire dependancy. And yes Jeff mentioned that the original Feedback node was implemented by an intern and they had thought he had chosen to implement it simply as a folded shift register but that seems to not have been the case and that is why it was much slower than a shift register. In 8.5 however Jeff claimed that the Feedback register should in all aspects we as user could possibly measure, behave exactly as a shift register. Probably there is also already an NI patent pending for it :-) Rolf Kalbermatter

QUOTE(wbiker @ Sep 7 2007, 04:02 AM) Most likely you either call some external code incorrectly when this event occurres or probably also possible you do not close properly some functionality contained in external code which makes it hang. Another possibility is that you have multiple loops in your application and one of them instead of exiting too, starts to run freely without any asynchronous delay function in it anymore. But without seeing some of your code and preferably a seriously scaled down application that exhibits still this behaviour it is not possible to give you more specific advice. Rolf Kalbermatter

QUOTE(TobyD @ Sep 6 2007, 10:32 AM) Or before there was VI server, like this: http://forums.lavag.org/index.php?act=attach&type=post&id=6875 Rolf Kalbermatter