infinitenothing

Many cameras have a soft trigger function. Maybe you could count images vs soft triggers before the exposure change to figure out the exposure of each image.

OK, I'm hearing overwhelming support for a web interface. Is anyone familiar with existing test data web services? I'm surprised I don't hear about this more often.

Lacking other input, I'll probably try and go with a django server since I like its database coupling.

How about this:

I'd like it if my test stations sent their test results to a web server. I'm wondering if anyone has done this. As I see it, I can probably do some port forwarding and expose a Maria/MySQL database over the internet or I could give that database a thin web interface and send the data over PUSH http requests. Are there pro/cons to one over the other? TLS is an option for either. Do you think HTTP would be more firewall friendly?

It's always a project by project decision for me. If I need the flexibility, I'll go TS. Otherwise, it's not worth the deployment licensing hassle.

Another advantage to rolling your own is you get to use LabVIEW's block diagram representation of the sequence. It's a great visual—things in parallel execute in parallel. Data flows on wires. What can I say?

FYI, regarding FP locking in event case: http://zone.ni.com/reference/en-XX/help/371361K-01/lvhowto/lock_fp/

Everything in the loop must complete before it can run again. Therefore, if the case structure is in the same loop as an event structure, they have a relationship and aren't really independent.

1 hour ago, ShaunR said:

The NI-9219 has a programmable constant current source and +-25mA is the range, isn't it?. The examples show a default excitation current of 50 or 100uA. I don't know what the resolution is off hand so don't know if it can go down to 10uA, though.

No not programmable

Quote

Excitation level is a characteristic and is not software-selectable

I've never had a problem with self heating but I've always had really good dissipation. I think if you need a lower current, you can use the half bridge method others linked to or a programmable current source like the 9265 with a second analog input module.

Why do you say the current would be too high with a 9219? The user manual say it would apply 2.2V which would be 400uA.

I guess if you wanted a lower current you could get a current source module and measure the resulting voltage with an analog input card to get resistance.

Try right clicking, saving the image to disk, and then drag the saved file from explorer to your block diagram. The snippet is in 2017 so if you need an earlier version you might have to ask someone to down convert it or... there's not that many blocks there, maybe you can try and recreate it.

I guess this is a "what's new in LV" thread now. There are some performance improvements in the conditional indexing tunnels on a for loop. I think it allocates the max size and trims it at the end. The async tools are also a huge performance increase over the old VI server method. Also, DVRs now allow parallel read access which is cool. The menu plugins provided many productivity improvements. VIMs make reuse easier.

Regarding the new dynamic refnum behavior, does everyone agree that the right terminal is more or less obsolete and could probably be replaced with something like a linked tunnel? Am I misunderstanding the new behavior?

Even VI server is going to have some drawbacks like accessing latching booleans and whatnot. If anyone has and idea exchange post in support of automated GUI test, I'd kudos it.

My example uses the second technique (subtracting a constant at IMAQ Subtract). Where are you getting these requirements from?

Also, it's nice if you let us know where you've cross posted this so we don't duplicate efforts

https://forums.ni.com/t5/LabVIEW/calculate-1-e-2-of-beam-intensity-profile-Measurement/td-p/3766062/page/2

https://forums.ni.com/t5/LabVIEW/Background-correction-and-Normalizing-Image/m-p/3766148#M1060967

That's a snippet so in theory, you should be able to just drag it into your block diagram negating the need for a VI file

Something like this?

The current behavior looks like the incoming reference on the left terminal overrides the previously "wired from the inside" right terminal. If that's the intended behavior, I feel like the the "right" terminal is now obsolete because of linked tunnels.

Not sure if we're still doing this but there's another subform for ideas:

https://lavag.org/forum/37-labview-feature-suggestions/

Are you looking for an automated tool or free labor? If it's the former, I don't know of one.

Maybe: http://zone.ni.com/reference/en-XX/help/371361H-01/lvhowto/hex_display/

Is this what you're looking for?

http://zone.ni.com/reference/en-XX/help/372916J-01/nivisionconcepts/supportvectormachines/

Have you tried the express VI? It looks like you don't need a shifter.

I don't entirely understand what you're getting at. When you say "searching the camera" are you talking about using something like IMAQdx Enumerate Cameras? And when you say "autorun to acquire figures" do you mean you're looking to use dataflow to delay when some events happen? That seems like a general purpose labview question and not a vision question. You'll probably want to use a sequence structure or a queue.

I'm not sure what the myRIO has built in (USBtoSerial drivers built in? CLIP?) but if you had to, you could always just program the FPGA and use a level shifter:

I'm guessing that's intended behavior since the two references are "equal" (see below). The problem is "when are two references equal". Different people might have different answers. It's too bad you can't "override" the equivalence operator with a functor replacing the "heart of the algorithm" 

It's a personal preference but I don't like using delete array for that purpose because I think it's confusing. I'm sure it costs me a few milliseconds when I see it and think "why would I want to delete an element from that array?" We want code that's easy to read not easy to write right?