Archived: LabVIEW 2011 Control Design and Simulation Module Known Issues

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Overview



This document contains known issues for the LabVIEW 2011 Control Design and Simulation Module. Not every issue known to NI will appear on this list; it is intended to only show the severe and more common issues that can be encountered.

Each Issue appears as a row in the table and includes these fields:
  • Issue ID
  • Legacy ID - The issue's legacy ID from NI's deprecated bug reporting database (if applicable)
  • Issue Title
  • Problem Description
  • Workaround
  • Reported Version - the earliest version of LabVIEW the issue was reported in
  • Resolved Version - version the issue was resolved or was no longer applicable
  • Date Added - the date the issue was added to the document (not reported date)

The LabVIEW 2011 Platform Known Issues contains a full listing of known issues, including LabVIEW toolkits and modules.

Contacting NI

You can contact us by phone, email, or the discussion forums. Visit the NI Website to contact us. If you are contacting NI in regards to a specific issue, be sure to reference the ID. If you have feedback on this document, please contact NI on this NI Developer Zone post.

Windows 7

National Instruments is committed to maintaining compatibility with Microsoft Windows technology changes. However, NI has become aware of a number of issues of potential significance regarding Microsoft Windows 7. To learn how Windows 7 affects your use of NI products, visit ni.com/info and enter the Info Code windows7.

Known Issues by Date

The following items are known issues in LabVIEW 2011 Control Design and Simulation Module sorted by Date.

145976Editing a Subsystem VI may not add asterisk (*) to title bar of caller VIs
156847Show Buffer Allocations does not work on simulation diagrams
159426Strange mouse pointer behavior using Control Design and Simulation on Mac and Linux
172558External model library interface does not automatically download to target.
89687 3SBBPSE9Cannot make root locus plots part of subplots
155420A Function Block Appears Twice in a Project When Dropped Inside Simulation Node
201449A Feedback Node on a Simulation Diagram causes the VI to fail to compile
224620Triggered Subsystems may not perform as expected in certain situations
229977VI with Simulation opens with broken run arrow but no errors
242420Direct Transfer Function, State Space, ZPK, and Discrete Filter VIs incorrectly output zero
172863Simulation Parameters of a subsystem do not update in the parameter tree
192062Cannot change dll that External Model function points to
194660Cannot set up a Single-Input Multiple-Ouputt system
258077LabVIEW crashes when compiling after wiring from a sink outside to a source inside a Simulation Node
305566Undoing an action in a subsystem results in broken a VI with the error "failed to compile"



IDKnown Issue
145976

Return
Editing a Subsystem VI may not add asterisk (*) to title bar of caller VIs
When making edits to a Subsystem VI, which will require recompiling the Subsystem's caller, an asterisk may not appear on the caller VI, indicating that it has changed. However, before closing the caller VI, LabVIEW will still prompt you to save the modified VI and there is no danger of unintentionally losing changes.

Workaround: N/A

Reported Version: 2009  Resolved Version: N/A  Added: 08/01/2009
156847

Return
Show Buffer Allocations does not work on simulation diagrams
Buffer allocation for arrays and clusters do not show up on a simulation loop or subsystem when using the show buffer allocations tool.

Workaround: N/A

Reported Version: 2009  Resolved Version: N/A  Added: 08/01/2009
159426

Return
Strange mouse pointer behavior using Control Design and Simulation on Mac and Linux
The first time you select an item from the Simulation Palette after each LabVIEW launch, it may fail to initialize and drop. Each time you select an item from the Simulation Palette the cursor may display a busy icon until the node is placed on the diagram.

Workaround: If item does not appear on the cursor, select it again from the palette. If the busy icon appears for an inordinate amount of time, try to place the node on the diagram.

Reported Version: 2009  Resolved Version: N/A  Added: 08/01/2009
172558

Return
External model library interface does not automatically download to target.
External model library interface does not automatically download to target.

Workaround: Place a Call Library Function node that points to the library and hide it behind a case structure that always executes the empty case. This causes RT to download the shared library to the target and load it when the VI runs, or ftp the file to the target.

Reported Version: 2009  Resolved Version: N/A  Added: 08/01/2009
89687
3SBBPSE9


Return
Cannot make root locus plots part of subplots
You cannot make root locus plots part of subplots.

Workaround: N/A

Reported Version: 2.1  Resolved Version: N/A  Added: 08/01/2009
155420

Return
A Function Block Appears Twice in a Project When Dropped Inside Simulation Node
When you drop a Function Block inside a Simulation Loop, the block and its parameters will be populated in the project twice.

Workaround: Place the Function block inside a subVI. This will prevent the second instance of the function block inside the project.

Reported Version: 8.6  Resolved Version: N/A  Added: 06/25/2010
201449

Return
A Feedback Node on a Simulation Diagram causes the VI to fail to compile
The Feedback Node does not make sense semantically within a Simulation Diagram, due to the fact that most ODE Solvers will execute the diagram multiple times per iteration and may need to reject steps and try again, filling the Feedback Node with bad data.

Workaround: Use the Memory block from the Simulation Utility palette. If a delay of greater than 1 is desired you can chain multiple memory blocks in sequence.

Reported Version: 8.5  Resolved Version: N/A  Added: 07/31/2010
224620

Return
Triggered Subsystems may not perform as expected in certain situations
There are two situations where a triggered subsystem may not perform as expected. First, if a node that uses the discrete step size as part of its calculations (such as the discrete integrator) is inside a triggered subsystem, the node will use the global discrete step size rather than the interval between triggers as the discrete step size for its calculations. For example, consider a discrete integrator in a simulation with a discrete step size of .1 inside a triggered subsystem. If the integrator has a constant value of 1 as its input, and it is triggered at t=2 and t=5, its output value after t=5 would be .1, not 2. Second, if a trigger occurs on a time step that is not also a discrete time step (i.e., the trigger occurs at t=1.5, and the discrete step size is set to 1), the triggered subsystem will execute, but none of the discrete nodes inside it will execute.

Workaround: N/A

Reported Version: 2010  Resolved Version: N/A  Added: 07/31/2010
229977

Return
VI with Simulation opens with broken run arrow but no errors
Sometimes a VI that uses Simulation from an earlier version of LabVIEW will be broken after opening. This could be a Subsystem VI or a VI with a Simulation Loop. Clicking the run arrow will open the Error List window, showing the broken VI, but no errors will be listed.

Workaround: Select any single node on the Simulation Diagram and choose Edit->Clean Up Diagram (Ctrl-U) Having selected a single node will mean that nothing gets moved by the Clean Up Diagram command, but the VI will become runnable.

Reported Version: 2010  Resolved Version: N/A  Added: 07/31/2010
242420

Return
Direct Transfer Function, State Space, ZPK, and Discrete Filter VIs incorrectly output zero
The Transfer Function, State Space, Zero-pole-gain, or Discrete Filter VIs will output only zero if the VI mode changes from indirect to direct through the parameter configuration page.

Workaround: Force a mode change through means other than the configuration page. For the discrete blocks, drag the block outside the simulation loop and then move it back.

Reported Version: 2010  Resolved Version: 2010 SP1  Added: 07/31/2010
172863

Return
Simulation Parameters of a subsystem do not update in the parameter tree
In the configuration dialog of a Subsystem placed outside of a simulation loop, Simulation Parameters do not update their values as you edit them. However they will be updated the next time the dialog is opened.

Workaround: N/A

Reported Version: 2009  Resolved Version: N/A  Added: 07/24/2011
192062

Return
Cannot change dll that External Model function points to
After an iniital dll has been selected for an External Model function, it cannot be changed. A user can select a different dll in the dialog but the change does not get saved.

Workaround: N/A

Reported Version: 2009  Resolved Version: N/A  Added: 07/24/2011
194660

Return
Cannot set up a Single-Input Multiple-Ouputt system
When trying to setup a Single-Input Multiple-Output system transfer function, the output reverts to a scalar (single output) when it should be an array (multiple output)

Workaround: N/A

Reported Version: 2009  Resolved Version: N/A  Added: 07/24/2011
258077

Return
LabVIEW crashes when compiling after wiring from a sink outside to a source inside a Simulation Node
When you try to wire a node from the outside of the simulation loop to a terminal inside Simulation, and make the tunnel "Use Default if Unwired", then the VI will fail to compile.

Workaround: There are two ways to work around this: 1) Start wiring operations across the Simulation Node boundary from the terminal inside the node. 2) Edit the simulation diagram and cause the VI to recompile.

Reported Version: 2010  Resolved Version: N/A  Added: 07/24/2011
305566

Return
Undoing an action in a subsystem results in broken a VI with the error "failed to compile"
Undoing edits to a subsystem so that it is in the state it was in at the last compiled causes the VI to be broken and report "failed to compile".

Workaround: Make an edit and it will force the VI to recompile

Reported Version: 2011  Resolved Version: N/A  Added: 07/24/2011

Document last updated on 7/30/2011

Glossary of Terms

 

  • Bug ID - When an issue is reported to NI, you may be given this ID or find it on ni.com.  You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
  • Legacy ID – An older issue ID that refers to the same issue.  You may instead find this issue ID in older known issues documents.
  • Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
  • Workaround - Possible ways to work around the problem.
  • Reported Version - The earliest version in which the issue was reported.
  • Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
  • Date Added - The date the issue was added to the document (not the reported date).