LabVIEW
Need help with a RS232 LabView program
Okay so I found out about NI MAX. I can find the COM port there as well. And the message says that the "resource is valid" even though it cannot connect. I guess that can't be too bad as a start...And I was also to "validate" the port:
Not sure if this is helpful at all...
Here's a possible example to get you started.
It should be true that you can run this VI and read the temperature - if that works, you can create more subVIs like the code indicated in the boxes here, and modify them appropriately to handle different commands.
I noticed reading again that there's a slight mistake in my parsing of the response.
If you check the string coming out of the VISA Read node, you'll probably get "<LF>T xxxx" (the <CR> will be handled as a term char).
I didn't handle the T, and so you might want to try tweaking the value of the "1" going into String Subset (e.g. if there's a space between T and the value, perhaps try 3, otherwise, you could consider 2... trial and error will get you there although I think Hex String to Number will be ok with the leading space anyway (edit, tested)).
I've spend the last hour trying to build a LabView script with your image....it is a mess. Just now I saw that you attached the file and I could have used this...well it was good training I guess.
What is up with SubVIs? creating these is messing up the whole structure
Ok, so the structure you used is pretty close looking to what I used, but not the same.
In my VI, I used flat boxes (from the Decorations subpalette of Structures) to indicate some grouping of bits within a VI that could be used to create a different VI.
In your VI (or at least this image below) you used Flat Sequence Structures, which have a functional behaviour (whereas mine were, you guessed it, decorative 😉 )
@Torracc wrote:
What is up with SubVIs? creating these is messing up the whole structure
To create a subVI from existing code, you can drag a box around it and go to Edit > Create SubVI..., and it will automatically connect it and make a new VI with an appropriate (or appropriate-ish) connector pane. This is the collection of bits in the top right of a front panel:
I'm not sure where in the tutorial material this is introduced, but it's like defining function parameters/arguments/return values in a text language - these are the inputs and outputs of a VI.
You just click on a box there, and then click on a control, and it is filled in. The colour indicates the data type. A small outline appears around outputs (indicators) to highlight them (here the blue icon, not really very visible). Usually put the inputs on the left and the outputs on the right for convenience when calling.
Double clicking on the icon opens the icon editor, which allows you to edit the icon (I know, right...).
The combination of these allow you to do something like the following with my example VI:
Project is attached (for 2015).
Edit: In response to your other questions, <CR> is carriage return and <LF> is line feed. These are marked as ^M and ^J respectively in your manual.
They are common line ending characters, on Windows the pair is used for an end of line (like <CR><LF>). On Linux, you commonly use <LF> and on Mac (at least previously, I believe modern Mac has changed to <LF>) you use(d) <CR>. This causes plenty of problems, but is an irrelevant aside for your LabVIEW driver.
@Henrik_Volkers wrote:
You have a first solution , but I'm curious why cbutchers solution with a 1 didn't work.
Because I didn't RTFM properly 😉 (that's F for full, btw...)
The command response is <cr>T xxxx<lf> and so with an offset of 1 you pass "T xxxx" to Hex String to Number. With an offset of 2 you get " xxxx" but the space is ok. 3 also removes the space.
