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Everything posted by Rolf Kalbermatter
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INI file and Flush File.vi - Error 1
Rolf Kalbermatter replied to Bruniii's topic in Database and File IO
It would have been a much more painful, and for most affected users even less trivial point to fix, if they replaced the original INI file fake refnum with a proper private user refnum. Any code that used a copy of that refnum in their own code somewhere would have simply broken. It was a judgment call: risk breaking a lot of existing code that improperly made a copy of that refnum or live with the limitations of the fake refnum. Not breaking existing code was always one of the top priorities in the LabVIEW development team, even if that existing code was born out of bad practice. And it's not ANY file API. Only file functions that legitimately can operate on datalog file refnums. And they properly generate an error 1, since the refnum in question is indeed NOT a valid file refnum. There are other situations where you can logically connect data types to nodes but that node can't operate on that specific flavor of data type. LabVIEW is strongly typed but sometimes there is simply no easy way to make sure at compile time. As long as it produces proper error codes at runtime and doesn't crash, I consider it a valid trade off. -
INI file and Flush File.vi - Error 1
Rolf Kalbermatter replied to Bruniii's topic in Database and File IO
About 30 years indeed. And bug is a strong word, it was a smart find back then to create your own refnums. While there would have been a better alternative around LabVIEW 7.1 (User refnums) there were several reasons not to use them. It was a new and not extremely well tested facility, it was really meant to incorporate binary shared library drivers with very little LabVIEW VIs and it would have broken the many Config File wrappers and application users that were creating a private copy of that βrefnumβ instead of using the Config File typedef. -
INI file and Flush File.vi - Error 1
Rolf Kalbermatter replied to Bruniii's topic in Database and File IO
Neil, that queue reference is type casted to a LabVIEW datalog refnum. This is done to create a custom refnum "light". It works to prevent users from connecting this refnum to anything that is not an INI refnum ....... except file IO functions that also can deal with datalog refnums. The file IO function then tries to extract the underlaying file handle and that of course fails since the queue refnum does not have a file handle. Therefore you get the error 1. If the OP really wants to hack a Flush into the library it would have to be added to the Config Close. But since this is the only time the whole file is even accessed with write access and there seems to be a little window of opportunity during the Write File function and the Close File function in there in which, when the power is yanked just in time, in the right way, the transfer to the disk is corrupted. The File Close should do a Flush too, although it may be somewhat delayed. How a Flush right before the Close would really help is more than doubtful. I think Shaun's recommendation to check the S.M.A.R.T data for the drive in question may have some real merits here! -
National instrument GITHUB repo NI/Linux
Rolf Kalbermatter replied to Youssef Menjour's topic in LabVIEW General
You can NOT install LabVIEW RT on non-NI hardware without a license from NI! And they have so far hesitated or stalled to say if they ever plan to sell such a license. What you can do is install NI Linux RT on whatever hardware you care since the Linux kernel is GPL software. And that is also what the NI Github repository is about. To provide a means to fulfill the GPL requirement to have the source code to the GPL covered software accessible to any user. What the NI Linux RT Github repository does NOT contain are the LabVIEW RT runtime kernel , NI-VISA, NI-DAQmx, NI-this and NI-that since they are closed source software and the Linux kernel comes with a special GPL clause that allows people to build and distribute closed source software that runs on it. Quite some kernel folks would love to get rid of that clause and force everybody to open source everything everywhere, but that didn't even fully work for kernel drivers, where they did a lot of effort to prevent closed source drivers from being able to do high performance operations. The big point here is that NI Linux RT is NOT LabVIEW RT. The whole LabVIEW RT runtime and NI driver stack are closed source and you can not install it on random hardware without an according agreement from NI. If you install NI Linux RT on your Jetson hardware, what you basically get is a somewhat expensive Raspberry Pi or Beaglebone Black board with additional soft RT capabilities but no LabVIEW target support at all! And no, the LabVIEW Hobbyist Toolkit can't be easily repurposed to run with such a hardware either. It's support is limited to ARM Cortex A hardware platforms and you may be able to get the according schroot image installed and running on the Jetson, but that is an entirely different thing than getting NI Linux RT installed on the Jetson. It is legally questionable but maybe you could get away with it, but it is technically quite a suboptimal solution as the schroot environment in which the LabVIEW RT kernel is running is a limited non-RT capable virtual machine running on the normal Linux host on your Jetson. -
Issues building applications in LabVIEW 2023 Q3
Rolf Kalbermatter replied to Mads's topic in Development Environment (IDE)
It happens in a lot of locations. When you go to the download page of NI software (their specific canonical download entry for each product where you can choose the version and bitness and such) you usually have a link that goes to another page that shows available readme's, and similar documents and there it often states this sentence. However it happens both for very old releases of software (I assume the person creating that entry felt to lazy or to frustrated to search the NI document management system for the according document) as well as very new releases (here the document may indeed not yet officially exist and has not been added to the document management system). -
Doesn't seem to have an MPSSEngine. Which is not so surprising. The MPSSEngine is a Multi Protocol Synchronous Serial Engine. There is nothing truly multiprotocol about the FT4222H chip, it's simply an I2C/SPI interface chip without support for other GPIO, RS232, and similar interfaces. https://www.ftdichip.com/old2020/Products/ICs/FT4222H.html You can use it through the FTD2xx driver though. there is also a LibFT4222 DLL which sits atop the FTD2xx driver and implements the FT4222 specific stuff. You would have to create LabVIEW Call Library Node wrappers for this DLL if you want to use this driver.
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Your suspicions are partly right! lvanlys.dll is for the most part the conversion layer from the LabVIEW AAL functions to the MKL. In old days lvanlys.dll was the NI implementation of the Advanced Analysis library. But when they changed to use the MKL they could (or did not want to) change the entire LabVIEW Call Library Nodes to adapt to the MKL entry points. Basically the MKL is NOT written with LabVIEW in mind but fully designed to be called by C(++) code. An intermediate translation layer written in C(++) that provides a LabVIEW friendly interface is the most easy thing to do in that case (no it's not easy at all but the alternatives are much worse in terms of effort and maintainability). Also there were some specific assumptions in the LabVIEW AAL that are slightly different how the MKL library expects things, so the lvanlys.dll also takes care of such differences. Alternative would have been to change some of the conditions for callers of the LabVIEW functions, which would have been a very serious backwards compatibility problem.
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The Intel Math Kernel Library. NI occasionally updates the Intel MKL used but doesn't painstakingly follow the latest and greatest from Intel. And there might have been some licensing perils in recent years. NI got a license to distribute the MKL when it was still its own product and Intel was very keen to have as many people as possible adopt it. Nowadays it is part of the One API initiative and Intel is a lot more pushy about monetizing that, so they may have altered the license deal that NI had, and NI might or might not have accepted that.
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Same as other mentioned. If your device comes with a proprietary serial protocol over RS-232, you can consider yourself lucky as at least the electrical layer of that interface is standardized. Alternatives are USB, which sometimes come with Virtual Serial Ports, making them on a similar level than good ol RS-232, but quite often require their own proprietary driver and only are compatible with the vendors software or an expensive SDK from them. Some vendors claim to have developed the super duper vendor independent communication standard, only to let you find out that they are really only compatible to themselves and sometimes not even across different series of instruments from the same manufacturer. They try to sell you their latest and greatest lab automation software that works perfectly with their devices and only sometimes in rather mediocre ways with other devices through complicated gateways and specially sold and expensive interface solutions. Generally it is a lot of marketing hype and sunshine, until you try to combine two or more systems from different vendors together.
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It's caused by new PCI transfer modes in recent chipsets for high end CPUs from Intel and AMD. The problem is not LabVIEW itself, which does not use any device drivers of its own, but one of the NI drivers you are using. Typically DAQmx and/or NI VISA are the main contender for this. The DAQmx release 2023Q3 or later supposedly has updated device drivers that will be able to deal with these new chipsets too. NI-VISA 2023Q3 or later should also be able to deal with these chipsets. The problem does not occur under Windows 10 since its PCI Plug & Play subsystem does not know about these new chipsets and doesn't try to initialize them to use these new modes.
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labVIEW2018 build EXE reports an error!
Rolf Kalbermatter replied to mooner's topic in LabVIEW General
More importantly the path to the DAQNavi.dll definitely is wrong! Yes it tries to find the DLL, which might or might not be there. No, it should NOT try to copy it into your application build. Any DLL located in the System folder got installed there by its respective installer. And should be placed there by that installer on any system you want to run an application that uses that DLL. LabVIEW has a particular treatment of the DLL library name in the Call Library Node. If the path specified there is only the shared library name without any path, it will let the OS search the DLL and Windows will automatically find it in the correct System directory. And the Application Builder will treat such a library name as indication to NOT include the DLL in the build. This CAN be important for custom DLLs that get installed in the System folder. It is ABSOLUTELY paramount and important to do for Windows standard DLL. If the path is not the library name alone, the Application Builder will try to copy the DLL to the built folder too and for Windows DLLs that means that the application will try to load that "private" copy of the DLL, and that goes catastrophically wrong for most Windows DLLs, as they rely on being located in the canonical System directory or all hell breaks loose. Try to edit all Call Library Nodes that use that DLL to only specify the DLL name alone without any path. The path usually looks like reverting back to full path, but that is a sort of quirk in the Call Library Node dialog. LabVIEW generally will attempt to update the path to where it actually got the DLL loaded from, yet it still stores the former user entered path in the VI itself. And are you using 64-bit LabVIEW 2018? Or a 32-bit Windows system? Otherwise that path is anyhow wrong. On a 64-bit Windows system, C:\Windows\System32 is for 64-bit DLLs. Unless your LabVIEW system is 64-bit too, that DLL in that folder definitely should not be the right one for your LabVIEW system. If the according installer put a 32-bit DLL in there, which would be pretty hard thanks to Windows path virtualization, this same Windows path virtualization will make it impossible for LabVIEW to reference that DLL there. -
[Request for feedback] Python visual scripting IDE
Rolf Kalbermatter replied to Jack Parmer's topic in LabVIEW General
You may want to reconsider trying to advertise this as a test sequencer competitor. Wiring together blocks is NOT a test sequencer by a long stretch. If that was the case there would be no Test Stand, since LabVIEW can do that already since 35 years. Users of applications like Test Stand expect a lot more than that. Maintenance of test limits, possibly with database backend, easy logging of results to databases, simple log and report file generation, ease of adaption of test conditions and test flow during production. Generally Test Stand and similar applications still require a lot of work to get a full test application together, but they do not require any programming for at least these sort of things anymore. I'm not a fan of the often hidden configuration for these things, but this is the added value proposal for Test Stand and friends that its users expect. Yet another flow chart application is not going to cut it for any of them. In terms of LabVIEW, there is obviously still a long way to go for Flojoy to get near to being a real contender in data flow programming. But I do definitely applaud you guys for the effort so far, and for the short time you are working on this thing, it looks already quite useful. The comparison with NodeRed looks pretty apt. I always found that rather limited in many ways compared to LabVIEW. A little like a Visio Flow Chart with some added execution logic behind it. Potentially useful but not quite able to implement more complex program logic that has many parameters flowing from a lot of nodes to even more other nodes. Some would probably say that that is an advantage as the complexity of a typical LabVIEW program can get overwhelming for a beginner. But I would rather have a bit to much complexity at the tips of my fingers than to run into all kinds of limitations after moving from simple node flow charts to real programs. -
AFAIK, documentation about this part of LabVIEW is only available as part of the cRIO C module development toolkit. And you had to sign a special agreement to get that. The part number is 779020-03 and it costs currently β¬ 6200 and has a delivery time of 85 days according to the NI order system, but it has no product page anymore and it is questionable that you can find anyone at NI who even knows what an MDK agreement is. AFAIK it included also an NDA section. The whole Elemental IO was developed for cRIO module drivers but its functionality was never really finished.
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For non-Linux systems and Linux systems before 2018 or 2019 you simply go into NI-Max and install the NICompactRIO Base image for the LabVIEW version you are using to target the controller. Here I installed CompactRIO 18.5 which is the version needed for the LabVIEW 2018 SP1 development system. there is a lot more installed on this controller but most is not really needed and will get removed in the final system setup. There is no "apt-get upgrade" on any NI cRIO system at all. For non NI Linux systems everything needs to be done from within NI Max. And in fact the base setup for the correct runtime system needs to be done even for NI Linux targets from your host machine. Once the base system is installed on NI Linux systems, you can then use opkg (not apt-get) on the command line through an SSH link to update the base package to possible bugfixes from the NI servers.
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If you upgraded the cRIO base system to LabVIEW 2018 I do not see how the old rtexe still could be running. It means the chassis got restarted several times, much of it got probably wiped for good and even if the old rtexe would still be there, it could not load into the new 2018 runtime that is now on the system. So yes for first tests it should be as simple as opening the main VI and pressing the Run button. Even if you had an old version of the application deployed to the target and set to run automatically (which would have to be done in LabVIEW 2018) LabVIEW will tell you that there is already a deployed application running on the target and that it needs to terminate that in order to upload the new VI code and then run it.
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Compile cRIO fails, Error -123002
Rolf Kalbermatter replied to Neon_Light's topic in LabVIEW General
That's the Unix way of creating interapplication mutexes. There are functions in Unix that allow for atomic check for this file and creating it if it doesn't exist and return a status that indicates if the file already existed (another process has gotten the lock first) or if it was created (we are allowed to use the locked resource). If that process then doesn't remove the lock file when it shutdown, for instance because it crashed unexpectedly, then the file remains on disk and prevents other instances of the process from starting. If you are sure that no other process is currently running, that could have created this lock, you can indeed delete it yourself. -
But those ASM source code files are just some glue code that were initially needed for linking CINs. CINs used originally platform specific methods to use object files as loadable modules. They then had to be able to link back to the LabVIEW kernel to call those manager functions and there was no easy method to do that in standard C. CallLVRT was the calling gate through which each of those functions had to go through when trying to call a LabVIEW manager function. In order to reference the internal LV function table required at that point assembly code to work and there were also some initialization stubs that were required. These assembly files were normally not really compiled as there were some link libraries too that did this, but I guess with 2.5, the release was a bit rushed and there were definitely files released in the cintools directory that were a bit broader than strictly needed. With LabVIEW 5 for 32-bit platforms (2000/95/98/NT) NI replaced this custom call gate to the LabVIEW kernel through a normal module export table. On these platforms the labview.lib link library replaced the CallLVRT call gate through a simple LoadLibrary/GetProcAddress interface. With LabVIEW 6i, which sacked Watcom C and the according Windows 3.1 release, the need for any special assembly files at least for the Windows platform was definitely history. There were strictly speaking 3 types of external code resources. CINs which could be loaded into a CIN node, LSBs which were a special form of object file that could be loaded and linked to by CINs (it was a method to have global resources that were used by multiple CINs) and then there were DRVRs which were similar to CINs but specifically meant to be used by the Device interface nodes. DRVRs were never documented for people outside NI but were an attempt to implement an interface for non-Macintosh platforms that resembled the Macintosh Device Manager API. In hindsight that interface was notoriously troubled. Most Macintosh APIs were notorious for exposing implementation private details to the caller, great for hackers but a total pita for application developers as you had to concern yourself with many details of structures that you had to pass around between APIs. And when Apple changed something internal in those APIs it required them to make all kinds of hacks to prevent older applications from crashing, and sometimes they succeeded in that and sometimes they did not! π serpdrv was a DRVR external code resource that translated the LabVIEW Device Interface node calls to the Windows COMM API.
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Never heard anything about the complete source code being accidentally released. And I doubt that actually happened. They did include much of the headers for all kinds of APIs in 2.5 and even 3.0 but that are just the headers, nothing more. Lots of those APIs were and still are considered undocumented for public consumption and in fact a lot of them have changed or were completely removed or at least removed from any export table that you could access. Basically, what was documented in the Code Interface Reference Manual was and is written in stone and there have been many efforts to make sure they don't change. Anything else can and often has been changed, moved, or even completely removed. The main reason to not document more than the absolutely necessary exported APIs is two fold. 1) Documenting such things is a LOT of work. Why do it for things that you consider not useful or even harmful for average users to call? 2) Anything officially documented is basically written in stone. No matter how much insight you get later on about how useless or wrong the API was, there is no way to change it later on or you risk crashes from customer code expecting the old API or behavior. Those .lib libraries are only the import libraries for those APIs. On Linux systems the ELF loader tries to search all the already loaded modules (including the process executable) for public functions in its export tables and only if that does not work will it search for the shared library image with the name defined in the linker hints and then try to link to that. On Windows there is no automatic way to have imported functions link to already loaded modules just by function name. Instead the DLL has to be loaded explicitly and at that point Windows checks if that module is already loaded and simply returns the handle to the loaded module if it is in memory. The functions are always resolved against a specific module name. The import library does something along these lines and can be generated automatically by Microsoft compilers when compiling the binary modules. HMODULE gLib = NULL; static MgErr GetLabVIEWHandle() { if (!gLib) { gLib = LoadLibraryA("LabVIEW.exe"); if (!gLib) { gLib = LoadLibraryA("lvrt.dll"); if (!gLib) { /* trying to load a few other possible images */ } } } if (gLib) return noErr; return loadErr; } MgErr DSSetHandleSize(UHandle h, size_t size) { MgErr (*pFunc)(UHandle h, size_t size); MgErr err = GetLabVIEWHandle(); if (!err) { pFunc = GetProcAddress(hLib, "DSSetHandleSize"); if (pFunc) { return pFunc(h, size); } } return err; } This is basically more or less what is in the labview.lib file. It's not exactly like this but gives a good idea. For each LabVIEW API (here the DSSetHandleSize function) a separate obj file is generated and they are then all put into the labview.lib file. Really not much to be seen in there. In addition the source code for 3.0 only compiled with the Apple CC. Metroworks for Apple, Watcom C 9.x and the bundled C Compiler for SunOS. None of them ever had heard anything about 64 bit CPUs which were still some 10 years in the future. And none was even remotely able to compile even C89 conformant C code. LabVIEW source code did a lot of effort to be cross platform, but the 32-bit pointer size was deeply engrained in a lot of code and required substantial refactoring to make 64-bit compilation possible for 2009. The code as is from 3.0 would never compile in any recent C compiler.
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Can I ride the LV/TS train to retirement?
Rolf Kalbermatter replied to Phillip Brooks's topic in LAVA Lounge
Interesting word π. Learned a new thing and that this was only invented in 2003. As to knowing English better than you do, you definitely give me more praise than I deserve. -
Can I ride the LV/TS train to retirement?
Rolf Kalbermatter replied to Phillip Brooks's topic in LAVA Lounge
Of course it looks familiar. When not programming LabVIEW (or the occasional Python app) I program mainly in C. It's easy to typecast and easy to go very much ashtray. C tries to be strictly typed and then offers typecasting where you can typecast a lizard into an elephant and back without any compiler complaints π. Runtime behavior however is an entirely different topic π€ -
I was just recently trying to find out where the cutoff point is. In my memory 2016 was the version that stopped with 32-bit support. But looking on the NI download page it claims that 2016 and 2017 are both 32-bit and 64-bit. But that download page is riddled with inconsistencies. For 2017 SP1 for Linux you can download a Full and Pro installer which are only 64-bit. Oddly enough the Full installer is larger than the Pro. The 2017 SP1 Runtime installer claims to support both 32-bit and 64-bit! For 2017 and 2016 only the Runtime installer is downloadable plus a Patch installer for the 2017 non-SP1 IDE, supposedly because they had no License Manager integration before 2017 SP1 on non-Windows platforms. Here too it claims the installer has 32-bit and 64-bit support. So if the information on that download page is somewhat accurate, the latest version for Linux that was still supporting 32-bit installation was 2017. 2017 SP1 was apparently only 64-bit. Of course it could also be that the download page is just indicating trash. It's not the only thing on that page that seems inconsistent.
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Can I ride the LV/TS train to retirement?
Rolf Kalbermatter replied to Phillip Brooks's topic in LAVA Lounge
Easy typecasting in C is the main reason for a lot of memory corruption problems, after buffer overflow errors, which can be also caused by typecasting. Yes I like the ability to typecast but it is the evil in the room that languages like Rust try to avoid in order to create more secure code. Typecasting and secure code are virtually exclusive things. -
It's the same that LabVIEW adopted many years ago when they added the PCRE function to the string palette in addition to their own older Match Pattern function that was obviously Perl inspired (and likely generated with Bison Yacc), but more limited (not necessarily a bad thing, PCRE is a real beast to tame π). Not sure about the exact version used in LabVIEW but since it appeared around LabVIEW 8.0 I think, it would be likely version 6.0 or maybe 5.0, although I'm sure they upgraded that in the meantime to a newer version and maybe even PCRE2.