Jump to content
News about the LabVIEW Wiki! Read more... ×


  • Content Count

  • Joined

  • Last visited

  • Days Won


drjdpowell last won the day on December 7

drjdpowell had the most liked content!

Community Reputation



About drjdpowell

  • Rank
    <customize this text>

Profile Information

  • Gender
  • Location
    Oxford, UK

LabVIEW Information

  • Version
    LabVIEW 2017
  • Since

Contact Methods

Recent Profile Visitors

6,123 profile views
  1. drjdpowell

    How do you model this?

    You're a bit late for this conversation, though the topic is still very relevant today.
  2. drjdpowell

    [CR] SQLite Library

    Tried inserting png, jpg, and bmp images (by solution 1) and they can be viewed by SQLite Expert Personal, which I use.
  3. drjdpowell

    [CR] SQLite Library

    I think your issue is the multitudes of "image" formats. There are many formats, and many conversion functions, and it is difficult to get things to work by trial and error. The webpage for "SQLite Administrator" indicates it understands JPG format, yet your attached code is converting from JPG to a LabVIEW-only flattened image format. You need to read that JPG image into a LabVIEW string, without converting it into some other format, and insert it. Look into the "Read form binary file"... (I see smithd has beaten me to it).
  4. drjdpowell

    [CR] SQLite Library

    "Seems not to work" is the vagueous description you could give, but I wonder why you aren't just saving your bmp image as a blob, rather than turning it into a LabVIEW image format (and then only storing part of that).
  5. drjdpowell

    [CR] SQLite Library

    What have you tried? Have you looked at the examples?
  6. drjdpowell

    [CR] SQLite Library

    BTW, the SQLite Statement class can be subclassed, and you could easily define your own strict-typed versions of the "Get Column" property nodes. These would just check type before calling the regular function.
  7. drjdpowell

    [CR] SQLite Library

    SQLite differs from other databases in its dynamic type system and philosophy of "best attempt at conversion instead of error". Note though that SQLite is meant as an embedded database, sitting behind an API written in another language. Types are enforceable in that API. I don't recall ever having mixed types in a column, because a table is generally only written to by one subVI, and maybe modified by another one right next to it in the same library/class. I have one client where there are four applications that access the same db files, but they all use the same LabVIEW class for access. The API even stores data points in a scaled format to take up less space, which is transparent to the application code.
  8. drjdpowell

    creating .json file

    No. You haven't given any information about your "normal" text file.
  9. drjdpowell

    creating .json file

  10. drjdpowell

    [CR] SQLite Library

    Save your image files in binary Blobs.
  11. drjdpowell

    OPC UA experience

    I made the Server a Client of itself, in order to get events when true Clients changed things. A bit weird.
  12. drjdpowell

    [LVTN] Messenger Library

    Here is the function I mentioned, BTW:
  13. drjdpowell

    [LVTN] Messenger Library

    Does your receiving actor know the exact reply address that the special sender will use? You can use addresses as unique identifiers with "equals". There is a vi in the palettes that searches an array of addresses for the reply address on an incoming message. Your design is different from ones I'm familiar with, so that may not be a good answer.
  14. drjdpowell

    [LVTN] Messenger Library

    This is Issue 9, the trickiest problem in Messenger Library at the moment. Can you try version 1.10.6, which is in the LAVA-CR (this has been submitted to the Tools Network and is working its way through the process. There is no ideal solution but this is my best attempt. Alternately, you can try renaming your Main:ActorNR to something else (assuming you don't need to launch it but are instead running it directly).
  15. drjdpowell

    [CR] SQLite Library

    The dll should be automatically included in any exe; does that not happen with you? I have not tried using older dlls, but I suspect the would work.

Important Information

By using this site, you agree to our Terms of Use.