Block diagram error

[Blockdiagram9]

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Hi, I'm working on a simple code with bunch of flat sequence structures and for loops. I suddenly got this error and Labview does not respond everytime I try to reopen the block diagram and shuts down at the end.. Labview version is 2015 sp1 and Os is Window7.. 

Thanks in advance for any help.

  

 

[santo_13]

Simply NO, if you're using sequence structure then you have not understood the Data Flow paradigm of LabVIEW. Unfortunately, none of us can debug images, I would guess that your implementation is so convoluted and complex that LabVIEW couldn't process it.

Please attach the VIs you've and describe your goals.

[GerdW]

Hi BD9,

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@Blockdiagram9 wrote:

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I suddenly got this error and Labview does not respond everytime I try to reopen the block diagram and shuts down at the end..

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I guess the block diagram grew too large. This typically happens for such cases…

Solution: get an older version of that VI(s) from your SCC tool (or from your backup).

Then start over from scratch by applying basic LabVIEW rules and paradigms. Ever heard of "THINK DATAFLOW!"?

[Bob_Schor]

Most LabVIEW functions have "Error In" and "Error Out" in the bottom corners of the Connector Pane.    (Almost) every VI that you write (and you should have "a goodly number", which keeps the size of the Block Diagram down, since a sub-VI is only 32 x 32 screen pixels in size) should also have Error In and Error Out on the lower corners of the Front Panel connectors.  It is much easier to read a Block Diagram where the Error Line, running from function to functions to sub-VI, shows the orderly sequence of (functional) steps without the Bloat of the Sequence Structure.

Did you ever learn the "Principles of Data Flow" when you first encountered LabVIEW?  If not, here are the three basic Principles (in LabVIEW terms):

1. A Function or Structure doesn't "run" until all of its inputs have data (which may need to flow in through a wire).
2. A Function or Structure doesn't "exit" until all of its outputs have data.  Until it does exit, none of its outputs will "express" their data (so any wire connected to it won't send data along the wire).
3. If two (or more) Structures/Functions have no wire path from the output of one to the input of another, you can't tell which executes first -- for all intents and purposes, they will execute in parallel.

If this doesn't make sense to you, try the following "experiment":

1. Open LabVIEW and create a new VI.
2. Inside the VI's Block Diagram, create a While Loop.  Right click the Stop indicator and choose "Connect Control" (which should drop a "Stop" button in there to stop the loop).
3. From the Time Palette, drop a Wait (ms) function and wire 60000 (60 thousand milliseconds = 60 seconds) to it.
4. Run this simple VI.  Predict what will happen if you immediately push the Stop Button.  Did it do what you predicted?

Bob Schor

1.  

[altenbach]

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@Blockdiagram9 wrote:

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Hi, I'm working on a simple code with bunch of flat sequence structures and for loops. I suddenly got this error and Labview does not respond everytime I try to reopen the block diagram and shuts down at the end..

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"Simple" is definitely the wrong word for any of this!!! 😮

From the pictures, you seem to be running into the maximum size of the diagram, and get graphics corruption. Start reading here. Still, this should not cause a shutdown unless the corruption is deeper. Do you get any error messages?

• How long did you wait after opening?
• What exactly "shuts down" at the end (This VI, LabVIEW, computer, etc.).
• How big is the VI on disk? Can you attach it?
• Do you separate compiled code or not?
• What does the task manager say when you try to open (CPU, memory, etc.)

Once we solve this, we can go to the next step a give you advice how to properly write LabVIEW code. This is definitely NOT it! Any VI that heavily relies on sequence structures is a hallmark of a beginner without much training. That should be an entirely new discussion and we recommend to go through the learning resources listed at the top of the forum first.

[JÞB]

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@Bob_Schor wrote:

Most LabVIEW functions have "Error In" and "Error Out" in the bottom corners of the Connector Pane.    (Almost) every VI that you write (and you should have "a goodly number", which keeps the size of the Block Diagram down, since a sub-VI is only 32 x 32 screen pixels in size) 

Bob Schor

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Not exactly. A VI Icon is 32x32 pixels on the block diagram.  A VI is the same width as an Express VI but with a yellowish background and may be expanded vertically to show up to 24 inputs and outputs.  You switch between the two views from the right click option "Show as Icon"

Useful when someone choses the high density connector pane and wiring becomes problematic.   It also FORCES all inputs on the left and all outputs from the right regardless of where they are on the connector pane.  I had to use that trick once and a CLA asked me, "What is THAT!?"  I said, "That is a VI! Haven't you ever seen a VI before?"  You could hear his jaw hit the floor from across the room.