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Posts posted by Tim_S

  1. On 3/8/2022 at 2:40 PM, HorseBattery_StapleGuy said:

    what is the competition of NI in price and capabilities

    I was looking at UEI products many years ago, but never had a project could use them on. At the time the PCI cards were very similar specs to NI at less cost, but the front end didn't appear to be as robust. They also had a 'cube' product where it was stackable boards on a base module; it looked interesting, but again didn't have a project that it would work on.

    Got a sister division that uses Beckoff remote I/O. The sampling rates would be slower. Recall the prices were pretty good for remote I/O systems when tried to get a feel for the product.


  2. 1 hour ago, HorseBattery_StapleGuy said:

    Are there any decent alternatives to NI hardware like analog input modules when it comes to DAQs?

    Well, yes and no and yes and maybe. It all depends on what you're trying to measure and what the system requirements are. And, of course, just because it's cheaper up front doesn't mean it's cheaper overall. If it costs $200 less but takes me 50 hours longer to implement then it costs more.

  3. 20 minutes ago, drjdpowell said:

    Does anyone actually use Variants in clusters in this way?  To me, this is not even a tertiary use case of JSONtext, so it would be helpful to hear from people with real-world uses.  I am tempted to suggest throwing a "Variants not supported" error, but even that would add overhead which I am loath to do.

    I've used them in that way pre-maps leveraging variant attributes. Don't expect JSONtext to handle that use case, though.

  4. 2 hours ago, FantasticNerd said:

    So normally I would start thinking about what had changed in the whole environment so that it will not work anymore.

    Were there an IT Firewall update?? Some Anti-Virus Software Updates? Have you or someone else changed the code? The hardware? The connection? Normally an Application does not behave different if nothing changes.


    Don't forget versions, updates and patches, particularly in operating systems. For example... had a customer call me with a station that was down after a couple years of running. It looked like a UDP communication issue between two PCs. Wireshark showed the UDP message showing up at the port, but the application didn't receive it. Eventually this was tracked down to the build of Windows 7 (1609, if I recall right) can randomly turn off a setting that UDP needed to work. The "fix" involved a registry edit, but it's waiting to happen again.

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  5. Not familiar enough with Linux or ZeroMQ to give a specific answer, but thinking this through... Segmentation fault is the program trying to access memory it's not supposed to. Certainly been able to do that on Windows, so I don't see why can't do the same with Linux. Typically get that when working with drivers, which ZeroMQ would qualify as. Could be something like passing a pointer that is or becomes invalid, or trying to access memory that has been freed up.

  6. The site is doing a sales pitch on it's front page. That's fine all sites do that. I'm already a customer so I go to the NI site for 1) product information, 2) support, or 3) downloads. It took me poking about a bit to find what was looking for as the navigation feels almost hidden up top. Now that I've got an idea of how the layout has changed I think I'm OK and it might be more navigable. Just got to ignore everything past the top inch of main page and all should be good. 

  7. Something the "supplied cables" reminded me of is that APC UPS (at least the ones I've been using) use a non-standard pinout on the DB9 for serial communication. The UPS comes with a cable with the correct pinout on each end. Any chance that's what's causing grief? 

  8. Don't know if this will work with your design, but... I have a similar situation of class reference to itself. The code is the base object for plugins and gets compiled into a packed library. The class has a vit inside of it that the child uses to create a version that it sets in a property. The property is strictly typed to the vit and gets called by the parent. To make this work I had to put a control of the reference in the library the parent class is in. This is the way I was able to get around a reference to a class within itself.



    • Like 1
  9. The only time I consistently use Defer Panel Updates is with a TreeView control, which is slow to update the display (particularly when creating hundreds of rows).

    Another strategy is to check for data change to see if an update is needed. But, really, it depends on what you're doing. A configuration/editing screen is driven by user actions, so one event trips multiple updates to the UI and Defer Panel Updates can be useful. A screen showing periodic data may update each message with no issues, or checks if anything needs to be updated and when it does may need to defer updates to do so quickly. Though if you have something like an informational/debug screen that is only shown when requested then might not update the front panel unless it's visible.

    10 minutes ago, hooovahh said:

    It feels like the lazy method

    Could put that as you've done the cost-benefit analysis and the improvement is not justified.  :) 

  10. I don't have the vision addon installed, so can't point you to a specific VI. I recall there being an example that performed a histogram of the colors (in RGB?). You may need to open up various vision examples as it might not specifically state it was a histogram example.

  11. I've gotten a test bench of 1 MS/sec of 32-bit data (24-bits plus 8-bits channel identifier) across FPGA->RT->Windows using DMA channel to RT FIFO to TCP and let it run overnight without drop of any data. Buffer was set to maximum size of U32. Now that was with a cRIO rather than a myRIO. 

    Are you using NI's recommendations for best practices? Particularly the one where you check for available (request 0 samples) and then read all is a good way to read on the RT side. If you wait until the buffer is full then the FPGA can (and almost certainly will) overwrite before host side can service an interrupt.

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