Rolf Kalbermatter

Well, the whole NI=>Emerson transaction seems to go as follows: 1) Shareholders from Emerson have approved the deal 2) Emerson created a wholly owned subsidiary in Deleware called Emersub CXIV, Inc for the whole purpose of merging with NI 3) Shareholders from NI approved the merger on June 29, 2023 4) After all the legalities have been dealt with National Instruments and Emersub CXIV, Inc will merge into a new company under the name of National Instruments, and Emersub CXIV, Inc will cease to exist. The end result is that National Instruments for a large part will most likely simply operate as is and be a fully owned subsidiary of Emerson Electric but for a lot of things simply keep operating as it did so far. If and what technical cross contamination will eventually happen will have to be seen. You could probably compare it to how National Instruments dealt with Digilent and MCC when they took them over. They both still operate under their own name and serve their specific target audience and for a large part were unaffected by the actual change in ownership. There were of course optimizations such as that most of the MCC boards where eventually actually manufactured and shipped from the same factory that also produces NI hardware. Digilent also has eventually taken over some of the products from NI that were mainly meant for the educational market such as myDAQ but also the Virtual Bench device which they sell under a different name but it is 100% the NI Virtual Bench device and also works with the same drivers.

There is no simple fix to that. In order to draw anything on a Windows GUI you do need GDI objects. Every Window is one, every subwindow, every icon or bimap is one, every line or arc could be one, every text can be even two or three. You can open them, draw them to the device context and close them afterwards but opening/creating them costs time so if you foresee to use them again it’s a pretty smart idea to keep them around instead of spending most of your program execution time in creating and destroying them continuously. The only thing LabVIEW programmers can do is to try to combine more operations into a single object and/or finding the objects that are rarely needed and pay the runtime performance penalty to recreate them each time instead of keeping them around. Also I’m pretty sure that 3D controls with alpha shading may look cool to some people but tend to increase the GDI object count substantially. Classic and Dialog controls are a lot easier to draw!

And the Scan From String does a greedy pattern match, this means the first %s will eat the entire string as any character matches %s and then there is nothing left for the other 7 %s to process => error 85 as the Scan from String can't satisfy the second %s. If you have a space as separation character as it seems you have from the format you show you should rather use following Scan From String format string %[^\s]\s%[^\s]\s%[^\s]\s%[^\s]\s%[^\s]\s%[^\s]\s%[^\s]\s%[^\s] For this you should also right click on the string constant and enable '\' Codes Display The format string basically says, take every character until you see a space and put this in the first output parameter, then take the space and repeat this for the remaining 7 output strings. Possibly 23 character could also mean that each substring consists of exactly 2 characters plus the 7 separation characters. If so you could also use: %2s\s%2s\s%2s\s%2s\s%2s\s%2s\s%2s\s%2s

You’re saying that an event registration terminal should behave like a tunnel? They are not the same thing as the name already says (and the symbol shows)! It’s also more like a shift register although the right side of a shift register can’t be unwired. And the behavior makes sense. For tunnels it can be a pitta to have to wire each output but it’s also desirable that it can be easily “reset”. And that behaviour was defined ca. 1986! For event registrations it is almost never needed to connect the right side terminal (I did that maybe once or twice in my entire LabVIEW programming). Alternative would have been to make only a terminal on the left side but then you couldn’t dynamically register an event. Inconsistent? Maybe if you take a puritan look, ,useful? Definitely! And I can assure you the LabVIEW team debated over this probably several weeks if not months before deciding on the current solution. The only improvement I could think of nowadays is to allow to hide the right side terminals!

That would be a management nightmare. There would be no possibility to handle more than one event registration to subscribe to the same even generator without very involved buffer management. By placing the event queue into the event registration object it is fairly simple. 1) Hey here is my event queue, post any event you get to it. 2) I only have to check that queue to see if there is any event to handle. Not some other queue that might or not might have events present that I already processed but need to remain in it because not all event registrations have yet gotten to read that event. There is a relatively cheap check needed in the event generator to see if the event registration queue is still valid before trying to post a new event to it but that’s much easier than turning the single.queue into a pseudo random access buffer for use with multiple registrations. Similarly the event registration needs to check that the event generator is still valid when trying to deregister itself from it on its own destruction but that’s again a fairly simple Is Not an Object/Refnum check.

That would make little sense. That event queue is owned by the registration refnum, and the registration refnum registers simply a callback in the event object. The event is able to have multiple callbacks registered as it "queues" them up internally. That's what makes it possible to have multiple registration refnums connected to the same event object. That makes resource management fairly easy, avoids polling and objects owning other objects. Once the event goes away it simply will stop posting any events to the registered callback (it forgets about the callback since it is non-existent). The event queue in the event registration object still exists until that event registration object itself is destroyed. And if you close the event registration refnum earlier it simply deregisters itself from the event.

It's not a bug and there is nothing that could be fixed here. The user event is not the same as the event registration! The user event is an event object that manages events in an internal FIFO queue to pass the event over to the event wait node AND/OR to any number of attached event registration handlers. When it is registered with the register node, a new independent object is created that contains its own event queue and that event registration is then connected to the event with an event registration handler that simply passes the event to this queue in addition to the internal event queue. Once the event is gone, all the events that are stored in the internal queue of the event are of course gone, but the events also were passed to the queue of every attached event registration queue. That queue remains valid until the event registration refnum is closed itself. The event registration is special as it can attach to any object that can expose an event interface, such as ActiveX objects, or .Net classes too (if they have defined events). Also LabVIEW front panel objects actually can provide an event interface and their refnum can be connected to a Register Event node.

crossrulz is very correct. VISA only supports TCP/IP and that in two flavors. The first with the ::INSTR postfix is according to the VXI-11 standard that provides a resource discovery service (ala Bonjour) on the device that allows NI Max to query for connected devices and query their specific settings. The second variant uses the ::SOCKET postfix and is raw TCP/IP communication. The resource specifier needs in that case also a port number in addition to the IPv4 device address. UDP communication in LabVIEW is only possible with the UDP native nodes in LabVIEW. No NI-MAX will be getting harmed nor in any other way getting involved in this!

Those handle functions only really worked on the Mac, since they were actually creating native MacOS handles, not the LabVIEW own flavor of them that was a sugar layer around the rather arcane Macintosh memory manager calls. Yes the Macintosh memory manager was famous for being not high performant and quite crash sensitive. It worked for most Macintosh applications sort of, but LabVIEW really was considered a stress test for it. It was also regularly stressing the Macintosh Programmer Workshop C compiler that the LabVIEW team used to build the product. It was quite a regular happening that NI had to request Apple support to build a new version of it with bigger symbol table space, in order for the compiler not to fatally crash during build of some of the larger C source files. When the multiplatform version was started some of the real cracks in the LabVIEW team actually prefered to develop and debug on the Sun Solaris version of LabVIEW, since the compiler and debugger tools where a lot more powerful on there, even though everything was in fact all command line based. And yes LabVIEW 2.5.x was Windows 3.1 only. It was never tested nor build to run under Windows 95 or later, which would have been very difficult considering that it was released in fall 1992. The first version supporting Windows 95 natively was AFAIK LabVIEW 4.0. LabVIEW 3.1 or thereabout did however have a version that could be installed on Windows NT 3.1.

I used to have a whole box of disks and CD ROMs of old versions, though nothing before 2.2.1 which was Mac Only. But after 30 years and 3 major relocations, almost all of this has eventually ended up in the big round archive called trash bin. It's just not practical to hold onto these forever, and that stuff actually weights quite a bit altogether. Not fun to carry around and also not fun to fill up storage space (that I seem to always have not enough).

Why do you think you need to downgrade NI-VISA? Does something not work? Have you tried anything? While you indeed usually need to have a NI driver version that is not more than 3 years higher than the LabVIEW IDE you are using, that is somewhat less of a program for NI-VISA. First most NI VISA functionality in LabVIEW is built in, so there are not a lot of VIs that an NI VISA installer could add to your LabVIEW installation. Maybe the example VIs, but I'm not even sure about that. Second, the NI-VISA API itself has been very stable over many years and there is little reason to believe that you would run into compatibility issues with a bigger version difference. Basically on the development system where you run the LabVIEW IDE, you should make sure that the versions do not differ to much, but on remote systems where you only intend to execute built applications, almost every version of VISA would work, but it is always a good idea to use at least the same version or newer as you used to develop/built your program.

Post your LabVIEW project for the DLL, the DLL and its header. And please do a save for previous for2020 or earlier.

It looks fairly ok. But you have a problem. You need to free that handle and that is not trivial. You need to call DSDisposeHdl() from the LabVIEW manager functions, however it depends on various things as to what DLL that function needs to come from. Most likely however does your DLL already export a helper function. Have you checked the header for your DLL? Isn’t there an additional function named DisposeLStr or similar exported? Calling that correctly will properly deallocate the handle after you are done with it. One small correction, COM either means a serial communication port or the underlying technology for ActiveX (Component Object Model). There is a separate Python module to handle COM interfaces but that works differently. Here you simply call classic DLL functions.

The closest in terms of no runtime cost would be Conditional Compile for CPU architecture: anything but x86, x64, arm32 and arm64 is Big Endian. Alternative would be to check the VI Server property for CPU type. My version of runtime check used to be to use MoveBlock to copy a two character string with different ASCII characters “BE” into an int16 and check its value to be equal to 0x4245

I always use Unflatten from String/Flatten to String. It even has a third Endianess selection to never byte swap. It may be not as fast as MoveBlock but has been fast enough so far for me. The only thing I don’t like about it is that it forces String on the flattened side but a Byte Array to String or String to Byte Array solves this. It would be trivial for the LabVIEW devs to allow Byte Array too, just a flag in the node properties that would need to change and should have been done so 20 years ago and set as default as a first step to allow the divorce of String==Byte Array assumption that still hampers proper adoption of non ASCII strings in LabVIEW. I even hacked a LabVIEW copy in the past to allow automatic adaption of the Unflatten from String Node to Byte Arrays but that was of course a completely undistributable hack. An according LabVIEW Idea Exchange suggestion from me was acknowledged by AQ himself but dismissed as highly unlikely to be implemented by LabVIEW R&D. https://forums.ni.com/t5/LabVIEW-Idea-Exchange/Allow-Unflatten-from-String-to-also-accept-an-Unsigned-Byte/idi-p/3968413

For anyone looking at this library, I did an update in LabVIEW 2009 to properly support both 32-bit and 64-bit LabVIEW without any potential trouble. https://forums.ni.com/t5/LabVIEW/LV-slows-down-extremely-when-having-large-contents-in-clipboard/m-p/4251413

More than one per state? No.

What is a panther programmer? How do you interface to it? Your problem description sounds mostly like a basic LabVIEW programmer problem. Have you done some online programming courses and tutorials? Do you know how to write a simple LabVIEW program?

It may be the printer or its printer driver.

Actually, there is no direct way to call it that I would know of, but it should be possible to send the according menu command to LabVIEW. But what do you want to do then? This is not a vi, but an internal LabVIEW dialog. It does use a front panel resource like what VIs use but it is not a VI, the entire programmatic handling is a C code function.

Please, follow a C programming course first and work through it until you get to the advanced topics including memory pointers! This is not LabVIEW but C programming. You are missing very fundamental pointer knowledge! testDataBlock.DataRecords = (DataArrayHdl)handle; Alternatively you can write the code directly like this. size_t len = offsetof(DataArrayRec, elms) + size * sizeof(DataRecord) if (!testDataBlock.dataRecords) { testDataBlock.dataRecords = (DataArrayHdl)DSNewHandle(len); if (!testDataBlock.dataRecords) err = mFullErr; } else { err = DSSetHandleSize((UHandle)testDataBlock.dataRecords, len); } And you need to do that every time again. testDataBlock is on the stack, this stack gets invalidated every time you leave your function. That is why we do a DSDisposeHandle() before leaving the function, to deallocate the previously allocated handle before the stack is invalidated and the handle lost forever.

I added my comments in the comments behind //// static MgErr PostDataMessage(LVUserEventRef rwer, int32_t adapterNr, DataRecord *dataPtr, int32_t numElements) { // when you create the variable "testDataBlock" everything in the block is made 0 with the use of {0} // dataRecords points to a memory location which has got an unknow size. At this time the pointer is a Null pointer maybe ? //// => wrong!! It is a NULL pointer so it is not an unknown size but an invalid pointer pointing nowhere! DataBlock testDataBlock = {0}; // Here you use the function "NumericArrayResize" to resize the memorylocation dataRecords points to //// yes, it is a LabVIEW handle and needs to be accordingly setup, but since it is never really passed to the LabVIEW diagram //// it would not strictly be necessary to allocate it as LabVIEW handle but it needs to have the exact memory layout so it is //// easiest to do that in this way, anything else is going to confuse you simply more!!!! MgErr err = NumericArrayResize(uL, 1, (UHandle*)&testDataBlock.dataRecords, 2 * numElements); if (!err) { testDataBlock.adapterNr = adapterNr; // Here you use MoveBlock to Move the data from the source location where dataPtr points, to the // correct location of testDataBlock. You use the (*(..)) because if you would have used // *testDataBlock.dataRecords->elms you did point at the beginning of testDataBlock and not to the begining of elms //// wrong!! It is simply for correct C operator precedence evaluation, -> has higher precedence and would be evaluated //// before the * (pointer dereference) operator and would give you a compiler error since testDataBlock.dataRecords //// has no elms member, but *testDataBlock.dataRecords has, and I prefer to use more brackets to make it simply more //// clear, so (*(testDataBlock.dataRecords)) but the inner brackets are not strictly needed as operator precedence //// rules work fine here (. structure access has higher precedence than * pointer dereference, just as we want it here) MoveBlock(dataPtr, (*(testDataBlock.dataRecords))->elms, numElements * sizof(DataRecord)); (*(testDataBlock.dataRecords))->dimSize = numElements; err = PostLVUserEvent(rwer, &testDataBlock); // (this was your comment): PostLVUserEvent does a deep copy so we need to deallocate this handle to avoid a memory leak //// right! the testDataBlock memory area is going away at exit of this function and the handle stored in too, so we need //// to deallocate it otherwise it is lost DSDisposeHandle(testDataBlock.dataRecords); } return err; } No no! Doing it yourself instead of letting LabVIEW do it is only making things only really worse. And you definitely and absolutely are doing the calculation wrong although it will be simply a to big allocation so at least you won't blow up your harddisk. 🙂 Something like this would be more accurate: size_t len = offsetof(DataArrayRec, elms) + size * sizeof(DataRecord) if (!handle) { handle = DSNewHandle(len); if (!handle) err = mFullErr; } else { err = DSSetHandleSize(handle, len); } Sorry mate, but this sounds gibberish and I have no idea what you mean.

There are many ways you can print and it is not entirely clear to me which one you use. If you use the method to have LabVIEW send a front panel to the (default) printer, what really happens is rather involved. LabVIEW has no idea if the printer is a real printer, using EPS, LPD/LPR, JetDirect or whatever else underlaying printer driver protocol. All it knows is that the printer driver supports a GDI interface (The Windows Graphic Device Interface specification that is also used to draw items on the screen) and it pretty much treats it exactly the same aside from some extra setup steps such as page size and orientation. What finally ends up on the printer is very specific on the quality of the printer driver and its ability to render each of the zig hundred GDI commands properly in a resulting output. It seems that the PDF printer driver you are using, does some shortcuts by not rendering everything itself but for instance letting rotated text be rendered by the Windows GDI subsystem itself and then reading the resulting bitmap and adding that into the PDF stream. A very valid procedure although of course not the highest quality result. Other PDF printer drivers may be a bit more developed and translate this properly into direct PDF commands, but they may cost something.

Unfortunately, the LabVIEW internal manager function that would return the list of enumerated fonts is not exported from the LabVIEW runtime. That would have been a lot easier and platform independent.

Well, with that much information we can only tell you: Good luck! What interface? What part do you want to make read only? What platform? What LabVIEW version? Can you show in a simple VI what you try to do and what you have done so far? Up to now, you basically only said that you need help and nothing else. You need to be a lot more specific in what is your problem!