Let the user choose the probe location on a wire

[X.]

Ther are 10 pages of suggestions coming up when typing "probe location on wire".

AFAIK, none of them addresses this irritating behavior of probes:

The probe icon will snap to some algorithmically determined location which might result in illegible data flow during debugging, or might end up in a region of the diagram far from where the critical action takes place.

I know that what matters should be the VALUE of the probe, but WHEN to check the probe value is also critical, and in a visual development environment, this time is determined by monitoring the data flow (among other methods). This is where this uncontrollable probe location can be annoying at times.

My suggestion: just as for labels, let the user choose the location of a probe anchor point on a wire (especially when it branches off).

[RavensFan]

I agree with you it would be nice to place the probe bubble where you want so it doesn't intefere with other bubbles or block diagram objects.  I gave the idea a kudo.

I don't quite understand your second paragraph and what you be about the "WHEN to check the probe value".  Could you clarify that.

[X.]

If I am interested in checking the value on a wire, say, before a quotient and remainder function (like the one cropped off in the bottom right), I want to be able to read THERE what probe number I need to check to read the value, without having to navigate upstream along the wire to find the corresponding probe number.

If I have followed the evolution of that value along a wire up to that function, I may have been able to catch the value when it came out of a shift register (as in my illustration), but that is not WHEN I am interested in that number. I am interested in it WHEN it reaches the target function. By that time, I have to reverse navigate to the probe location.

Anyway, I think it is pretty clear that the current state of affair is not very satisfactory. Ideally I would want the equivalent of the pop-up value (for numeric) that shows at boundary crossing, to also show up next to that modified probe location, so that I don't have to look for the probe window, but that is not going to happen, so let's stick to the incremental feature of that suggestion.

[RavensFan]

I agree with having the probe bubble where you want to see it easily.  The talk of the value flowing down the wire and seeing the value when it hits the bubble vs. when it hits the function is nonsense.  The time it takes for a value to flow along the wire is just a graphical construction to help show the "dataflow" of data along the wire from one source, to one or more sinks.  In reality, the wire represents a single space in memory.  The data that is in the wire at the beginning of the wire is the same as it is when it hits each of the sinking functions, instantaneous, even though highlight execution shows it as a slow flow over a couple seconds..

[Intaris]

I have to disagree with RavensFan here.  While he may be correct that the value at the start and end of the wire is the same there can be a time differential of several seconds and many screen pixels in between.  With several probes on wires it can be hard sometimes to perform the mental act of remembering what changed when.  The ability to actually have SHOWN values on the wird of related values actually next to each other on the BD instead of far away is, I would have thought, of obvious value.

It wont give a different value but being able to do what is asked is simply making assigning any given value change to a desired probe a little easier.

[X.]

Like Intaris said.

The fact that we cannot control the speed of the data flow bullets is what creates this "WHEN" problem.

Now, you can blame me for sprawling diagrams that create this deadly combination of spatio-temporal dilation, but unless LabVIEW wants to reduce their market share even more, it might be wise for them to factor in the real world (and percentage-wise, I suspet, the majority of) use case of their language.

I'd be happy to bring up a bunch of NI-authored diagrams as demonstration of my point.

[AristosQueue (NI)]

> While he may be correct that the value at the start and end of the

> wire is the same there can be a time differential of several seconds

> and many screen pixels in between.

Are you talking about when execution highlighting is turned on? There's no correlation between position on a wire and when a highlight dot will reach that position -- speed of the execution dots changes depending upon how many parallel wires are being drawn at the same time.

The value on the wire is updated for the entire wire at the moment the source is written. That is the moment when the value changes. Moving the probe dot further down the wire won't change anything about when the value gets updated. When the graphics gets around to drawing execution highlight for a wire, the value has long ago changed.

[X.]

I'll explain what Intaris understood once I have a moment. It is precisely execution highlighting I was referring to and the sluggishness of the thing that makes it difficult to keep track of where the probe is corresponding to that wire that you are focusing on at coordinate (X,Y) of the diagram.

[RavensFan]

As I said,  I agree with the idea of placing the probe bubble wherever you want on the wire and kudoed the idea for that.

But it has nothing to do with execution highlight.  I just confrimed what Aristoqueue says.  The probe display does update as soon as that wire starts to execute, even though it might take a few seconds for the dot to flow down the line and flow past the bubble.

[Intaris]

Yeah I think i was writing more about  execution highlighting (and wanting to keep related values closer together onn the BD) than probes.  Sorry for the noise.

[X.]

I think we agree that the wire value is "instantaneously" propagated wherever that wire is connected. That wasn't the issue.

The issue is that while debugging with excecution highlighted, we may face the following issue:

In debug mode, here is where I am sent first:

By that time already, the wire doesn't show the value anymore.

Next we go here:

By the time we are here, I need to retrace the wire back to the probe location so that I can then refer to the probe window and check its value.

Had debugging highlight proceeded from the probe location to "PART 2" of the diagram, I MAY have remembered the value transiently displayed at the beginning of the debugging session during the time it would have taken the data bullet to go from the Numeric Control to PART 2 of the diagram.

This is the only thing I meant when referring to the time at which the value was checked,