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smithd

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Everything posted by smithd

  1. guys this was literally october of last year please stop bumping it and yes, I know this is the forum equivalent of reply-all "please unsubscribe me from this mailing list" at work. no way around it 👻
  2. For fun I thought I'd make a list of the reasons I can remember why people choose sometimes choose UDP over TCP. Connection overhead of TCP (initiating a connection) Mainly a big deal with web browsers (each page has to connect to several domains, and each takes a few (usually 2 I believe) TCP connections, which introduces latency) This is part of why HTTP/3 exists Not a big deal for a 2 hour test where you open one connection Don't need packet de-duplication or re-transmits video streaming or there
  3. On a closed network where lost packets are unlikely, TCP with nagle turned off should have minimal overhead/latency vs udp. Is there any way to send the ARP manually -- IE call into the winsock api (PharLap ) and force an ARP every 5 minutes to refresh the table?
  4. it also needs fpga: https://www.ni.com/pdf/manuals/378049a.pdf
  5. The usual reason files are missing from that menu is if you don't have LabVIEW FPGA installed, or if you installed a new software package and didn't re-install the drivers (vision acquisition, rio, etc). I've only ever used the flexrio-based cameralink card but I think the driver is slightly different.
  6. 2013 is my go-to for stable+old. 2010+11 had the new compiler, 12...I dunno what happened with 12, but it sure seemed to be unstable. Its probably a lie that my brain made up, but it always seems like the even years are much worse than the odd years, with the exception being that 2018 seems pretty solid. 2013 has the new compiler (2010) with the performance issues resolved (2012), auto-concatenating terminals (2012), somewhat improved web service scheme, get class instance by name, dotnet CLR got bumped to 4.0 (I know this may be a negative to you ). The only big issue I know of is the a
  7. Not sure if this was a typo, but RT-FIFOs are between loops on the RT side. You would use a Host-to-Target FPGA FIFO to pass data down to the FPGA for output. These fifo types do not support clusters, so you'd have to develop your own scheme for passing data down. This may be as simple as sending values in chunks of N, but you do have to watch out for overflows. If you are sending data from RT to FPGA there is a likelihood of underflow, depending on the output rate. You would probably wish to load all your file data into the fifo first and then tell the FPGA to start reading. This all dep
  8. I'm definitely not expecting anything he said to be set in stone, I was just curious about the concept. And to reinforce one of the bigger use cases that comes to mind for me That sounds like a pretty cool concept. I don't really have any more specific thoughts, it just sounds like a nice way forward. I do have one more somewhat related...I guess question, that comes to mind. So I think for me the exciting part is all of the reference lifetime-related stuff, but your first bullet point is improved memory management for large data sets. Most large data sets are such because
  9. Fair enough on all the above -- I think the answer is that we are agreeing for the most part, I'm just being pushy 🧐 . To follow up on the above and on AQ's point, my last comment was more or less attempting to reach this question, but didn't quite get there: How does this work together with the existing system? I think most of my questions and comments above were basically revolving around how these concepts apply within the world of a normal VI. To try to illustrate what I'm getting at, I'll go back to my vision application above. If I understand you, it seems like the way it is no
  10. Most of your responses made sense so I'm just going to pick out the few bits that made less: The local variable lifetime is kind of my point -- its life isn't really limited because the data space for a reentrant VI remains live for the duration of an application. Similarly, I was under the impression the shift register value is also permanent. As an example, I seem to recall a while back running a loop that allocates a giant (>>1mb) array on a shift register but never wire it out of the VI. if you do that, the large array remains part of the VI's data usage. From the perspective
  11. Definitely Kudod, but Mercer's responses sound like this is never gonna happen. The abort button thing in particular seems to also apply to rebar, although it's not clear if the nxg abort has the same semantics. I like your point on references, but the counter is also good to bring up -- since everything is top level, reliable sharing is impossible between two things with different lifetimes unless one is always long lived and defined as the owner. This is often fine, but it can bite people who are unaware.
  12. It seems interesting, and very cool that NXG lets you do stuff like this, but I do have some questions and comments. All of the below is without having installed it. I tried, but it requires NI package manager 19. NIPM 19 is not released as far as I can tell (I downloaded the latest, 18.5.1, from ni.com and when it loads it doesn't seem able to reach the server). More to the point, why does NIPM continuously have this issue where it requires a specific version to unpack the files? I honestly don't think I've ever successfully installed a package with NIPM on the first go <_<
  13. I'm guessing shaun would say this one: https://lvs-tools.co.uk/software/websocket-api-labview-library/ But the one on vipm seems good enough to me. A lot of the others are only 1 half or the other.
  14. Yeah websockets are easy, theres 12 libraries out there for setting them up using the tcp primitives. 50 ms delay could be nagle -- if its a closed network, 50 ms is at least 25 round trips, likely more. One possibility for the long long delay is if you're using hostname rather than numeric IP address. The hostname lookup is a disaster for any networking code, at least on windows.
  15. When you say cdaq, you mean normal cdaq or one of windows/rt cdaqs? Assuming windows/rt, maybe if you want some basic messages just set up a web service with a named queue to forward messages to. Then you don't need an actor, just call the http api directly (or spawn it as a task).
  16. DAQmx might not work right unless you increase the thread count, depending on how many of those actors have blocking functions
  17. Its worth mentioning that LabVIEW should do this for you, its called loop invariant code motion, so don't worry about it for performance reasons.You should put the code wherever its more readable. In this case, I'd argue the most readable form is leaving the math where it is, but moving the source values (array size, iteration terminal, control) closer in. I'd also say use a local variable for the control -- the downside to this is that, in fact, using a local variable will stop the loop invariant code motion from happening 😕 In this particular case, I'd like to mention that you can
  18. Ah yeah I read a note that said a specific visual studio version was no longer supported, should have scrolled down further.
  19. Yeah I looked again, I don't think matlab can use visual studio. Nah this is a parsing problem. Maybe I'm misreading the error but it looks like it doesn't know what __cdecl is -- __cdecl is visual studio specific. Since I think most compilers use that calling convention by default, you can safely remove all instances of __cdecl from stim.h
  20. I have two answers which might help: Answer A: Purchase Teststand and learn it. Without specific details I cant be sure, but it looks like the sort of application teststand is built for. If someone gives you crap about the cost, I'd argue that for sequential things like you've shown here teststand is a lot more maintainable (the bus factor for the code above is likely 1, and potentially 0 after a few months away from it). I'd also add that it has a lot of standardized reporting stuff built in...and if you're calibrating stuff, this would seem to be critical. So seriously, at least let som
  21. Fair enough, its definitely been a while. Last I remember I had to have the whole visual C sdk on my machine because it wanted to find some standard header. To me this is one of the bigger annoyances -- I dont' want to fix up the h file, that seems iffy to me. I suppose it generally doesn't matter since its just use to help the script along, but... Usually strings and arrays are OK, but yeah big structs can be iffy due to offsets -- that is once nice thing about this LLVM-based tool, is it tells you all the byte offsets so technically one could pass in an appropriately sized bu
  22. My understanding from what came up is that Matlab is attempting to build a wrapper dll with some more matlab friendly interface. A quick google didn't find me anything about how it does this, but that seems to be what its doing. I say that because the "we dont know the..." come from the labview headers. So it seems like Matlab is running a compiler against stim.h which includes the platdefines header, and since I'm assuming the matlab compiler is not one of the ones NI was expecting when they built this (or if matlab simply doesn't #define the same definitions NI is expecting), the compiler co
  23. If I had to guess, you'll want to edit STIM.h to include (at the very top, before anything else): #define _Win64 1 //if 64 bit #define _Win32 1 //any windows #define _M_AMD64 100 #define _M_X64 100 // same as above #define __x86_64__ // and again, this might be the gcc version or something? #define _MSC_VER 1900 // just a guess, this is ms visual c 2015 The full list of visual c #defines is here at this link, and you can also just go through the NI header file and look for stuff that makes sense. https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros?view=vs-2017
  24. just curious if anyone has ever made an attempt to improve scripting out of dlls. I know theres the built in import wizard, but I've literally never seen that work (has anyone here?). The reason i'm asking is that I was thinking about it and came across this tool: https://github.com/CastXML/CastXML (binaries from the build link at the bottom here: https://github.com/CastXML/CastXMLSuperbuild) Essentially it takes a C header (or any C file I guess) and processes it with LLVM to produce an XML tree of all the functions and types. For example it takes the header here: https://git
  25. Also, this is kind of a side point but the concept is the same. Has anyone noticed that reentrant VIs get super slow sometimes when debugging? Its not always, but I can't figure out what conditions might be causing it. Its like you're going along debugging some code, you step into a reentrant VI, and everything just stops, and it takes like 20-30 seconds for the window to materialize. I know its not just one computer, sadly.
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