LabVIEW 2018 Real-Time Module Known Issues

Publish Date: Feb 15, 2019 | 0 Ratings | 0.00 out of 5 | Print

Overview

This document contains known issues for the LabVIEW 2018 Real-Time 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.

The LabVIEW 2018 Platform Known Issues contains a full listing of known issues, including LabVIEW toolkits and modules.

Known Issues by Date

The following items are known issues in sorted by Date.

399608 RT FIFO writes produce high level of jitter on Linux-RT targets
540869 Behavior of App.Kind Property Node in Linux x64 RT targets Embedded UI Returns Invalid Property
541200 Cursor Reference returned by the Cursor Move event not valid on LinuxRT x64 target with the Embedded UI enabled.
543061 Error 56 Thrown When Using "Disconnect from Slave" Invoke Method
553905 Mass Compile Fails when using VIs from the RT Utilities Palette
567919 Creating an User Named 'lvuser' on NI Linux Real-Time Overrides Native 'lvuser' Account
580414 RT LEDs VI Returns Incorrect Error Code on Invalid Input
514879 - Running a VI Using Invoke Node Fails When Embedded UI is Enabled
606691 Calibration procedure of Touch Screen Monitor in NI Linux Real-Time Does Not Adapt to Screen Resolution
654235 If 2 classes call separate instances of a polymorphic VI and an instance is included within the a class, the VI will break when compiled into an RTEXE.
677278 Directory permissions may change on NI Linux Real-Time when modifying files via WebDAV.
700007 CPU load may be incorrectly reported when using Timed Loops on NI Linux Real-Time



ID Known Issue
399608

Return
RT FIFO writes produce high level of jitter on Linux-RT targets
On Linux-RT ZYNQ based targets, writes to an RT FIFO can introduce a high level of jitter compared to VxWorks and PharLap targets when the RT FIFO read occurs on a thread running in a different processor core.

Workaround: Prioritize RT FIFO read and write operations so they take place in threads running on the same processor core.

Reported Version: 2013    Resolved Version: N/A    Added: 07/22/2013
540869

Return
Behavior of App.Kind Property Node in Linux x64 RT targets Embedded UI Returns Invalid Property
Querying the App.Kind property returns Run-time System regardless of whether it is in development or executable state

Workaround: N/A

Reported Version: 2014 SP1    Resolved Version: N/A    Added: 03/08/2016
541200

Return
Cursor Reference returned by the Cursor Move event not valid on LinuxRT x64 target with the Embedded UI enabled.
When obtaining the cursor reference returned by the cursor move event, the output is not valid on NI Linux Real-Time x64 targets with the Embedded UI enabled

Workaround: Obtain the reference from a graph control property node

Reported Version: 2014 SP1    Resolved Version: N/A    Added: 03/08/2016
543061

Return
Error 56 Thrown When Using "Disconnect from Slave" Invoke Method
Using the "Disconnect from Slave" invoke method will almost immediately generate error 56; however the method functions correctly and disconnects the NI Real-Time system from the host machine.

Workaround: Ignore error

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016
553905

Return
Mass Compile Fails when using VIs from the RT Utilities Palette
If a VI running on an RT target uses a subVI from the RT Utilities palette, the VI cannot be mass compiled without errors as long as the project or VI are open during the compile.

Workaround: Close the project and VI and run the mass compile again. It should run successfully.

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016
567919

Return
Creating an User Named 'lvuser' on NI Linux Real-Time Overrides Native 'lvuser' Account
When using the Web-based Configuration & Monitoring tool to create or edit user accounts on a Linux RT target, the WIF allows creation of an account named "lvuser" or any of the other native Linux RT user accounts. Creating an account of the same name overrides the privileges of the native account. The default privileges for a new account are the same as the "Everyone" group, but not the "Admin" group. Unless admin permissions are added to this new account, issues can crop up using this account.

Workaround: Avoid adding an 'lvuser' account or make sure this new account has admin privileges.

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016
514879

Return
Running a VI Using Invoke Node Fails When Embedded UI is Enabled
When Embedded UI is enabled, using a LabVIEW Invoke Node to run a VI on NI Linux Real-Time results in an error about the Front Panel not being available. Using an Invoke Node to run a VI on NI Linux Real-Time works as expected if Embedded UI is disabled.

Workaround: Instead of using an Invoke Node, use the Start Asynchronous Call with the connector pane of the target VI wired into the Open VI Ref.

Reported Version: Unknown    Resolved Version: N/A    Added: 05/19/2017
580414

Return
RT LEDs VI Returns Incorrect Error Code on Invalid Input
When selecting invalid parameter for a cRIO controller for the RT LED VI the error code and origin is incorrect. It should be error code one and the source should point to the RT LED.vi

Workaround: N/A

Reported Version: 2015    Resolved Version: N/A    Added: 03/29/2016
606691

Return
Calibration procedure of Touch Screen Monitor in NI Linux Real-Time Does Not Adapt to Screen Resolution
Running the calibration procedure in something other than the maximum resolution of the touch monitor will cause some of the calibration points to be outside of the visible screen area. Thus the calibration procedure can not be completed and will be aborted.

Workaround: Calibrate with maximum screen resolution orIn an open terminal, type "xinput_calibrator --geometry WxH", where W is the screen width in pixels and H is the screen height in pixels.

Reported Version: 2016    Resolved Version: 2018 SP1    Added: 05/19/2017
654235

Return
If 2 classes call separate instances of a polymorphic VI and an instance is included within the a class, the VI will break when compiled into an RTEXE.
A VI will break when compiled into an RTEXE if the VI contains multiple classes that call a polymorphic VI and the a copy of the polymorphic VI is in one of the classes.

Workaround: Add the polymorphic VI to each instance of the class.

Reported Version: 2016    Resolved Version: N/A    Added: 05/19/2018
677278

Return
Directory permissions may change on NI Linux Real-Time when modifying files via WebDAV.
When modifying a directory via WebDAV on NI Linux Real-Time, the directory permissions may change to read-only.

Workaround: Manually change the permissions back to read and write access as necessary.

Reported Version: 2017    Resolved Version: N/A    Added: 05/19/2018
700007

Return
CPU load may be incorrectly reported when using Timed Loops on NI Linux Real-Time
In NI Linux Real-Time, the CPULoadTotal property node may incorrectly report the CPU Load when Timed Loops are used as part of the application.

Workaround: N/A

Reported Version: 2017    Resolved Version: N/A    Added: 06/04/2018

Known Issues by Category

The following items are known issues in sorted by Category.

Documentation
580414 RT LEDs VI Returns Incorrect Error Code on Invalid Input
Functions, VIs, and Express VIs
399608 RT FIFO writes produce high level of jitter on Linux-RT targets
540869 Behavior of App.Kind Property Node in Linux x64 RT targets Embedded UI Returns Invalid Property
541200 Cursor Reference returned by the Cursor Move event not valid on LinuxRT x64 target with the Embedded UI enabled.
567919 Creating an User Named 'lvuser' on NI Linux Real-Time Overrides Native 'lvuser' Account
514879 - Running a VI Using Invoke Node Fails When Embedded UI is Enabled
LabVIEW Project
553905 Mass Compile Fails when using VIs from the RT Utilities Palette
654235 If 2 classes call separate instances of a polymorphic VI and an instance is included within the a class, the VI will break when compiled into an RTEXE.
Miscellaneous
606691 Calibration procedure of Touch Screen Monitor in NI Linux Real-Time Does Not Adapt to Screen Resolution
Operating System Specific
677278 Directory permissions may change on NI Linux Real-Time when modifying files via WebDAV.
700007 CPU load may be incorrectly reported when using Timed Loops on NI Linux Real-Time
Remote Target
543061 Error 56 Thrown When Using "Disconnect from Slave" Invoke Method



ID Known Issue
Documentation
580414

Return
RT LEDs VI Returns Incorrect Error Code on Invalid Input
When selecting invalid parameter for a cRIO controller for the RT LED VI the error code and origin is incorrect. It should be error code one and the source should point to the RT LED.vi

Workaround: N/A

Reported Version: 2015    Resolved Version: N/A    Added: 03/29/2016
Functions, VIs, and Express VIs
399608

Return
RT FIFO writes produce high level of jitter on Linux-RT targets
On Linux-RT ZYNQ based targets, writes to an RT FIFO can introduce a high level of jitter compared to VxWorks and PharLap targets when the RT FIFO read occurs on a thread running in a different processor core.

Workaround: Prioritize RT FIFO read and write operations so they take place in threads running on the same processor core.

Reported Version: 2013    Resolved Version: N/A    Added: 07/22/2013
540869

Return
Behavior of App.Kind Property Node in Linux x64 RT targets Embedded UI Returns Invalid Property
Querying the App.Kind property returns Run-time System regardless of whether it is in development or executable state

Workaround: N/A

Reported Version: 2014 SP1    Resolved Version: N/A    Added: 03/08/2016
541200

Return
Cursor Reference returned by the Cursor Move event not valid on LinuxRT x64 target with the Embedded UI enabled.
When obtaining the cursor reference returned by the cursor move event, the output is not valid on NI Linux Real-Time x64 targets with the Embedded UI enabled

Workaround: Obtain the reference from a graph control property node

Reported Version: 2014 SP1    Resolved Version: N/A    Added: 03/08/2016
567919

Return
Creating an User Named 'lvuser' on NI Linux Real-Time Overrides Native 'lvuser' Account
When using the Web-based Configuration & Monitoring tool to create or edit user accounts on a Linux RT target, the WIF allows creation of an account named "lvuser" or any of the other native Linux RT user accounts. Creating an account of the same name overrides the privileges of the native account. The default privileges for a new account are the same as the "Everyone" group, but not the "Admin" group. Unless admin permissions are added to this new account, issues can crop up using this account.

Workaround: Avoid adding an 'lvuser' account or make sure this new account has admin privileges.

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016
514879

Return
Running a VI Using Invoke Node Fails When Embedded UI is Enabled
When Embedded UI is enabled, using a LabVIEW Invoke Node to run a VI on NI Linux Real-Time results in an error about the Front Panel not being available. Using an Invoke Node to run a VI on NI Linux Real-Time works as expected if Embedded UI is disabled.

Workaround: Instead of using an Invoke Node, use the Start Asynchronous Call with the connector pane of the target VI wired into the Open VI Ref.

Reported Version: Unknown    Resolved Version: N/A    Added: 05/19/2017
LabVIEW Project
553905

Return
Mass Compile Fails when using VIs from the RT Utilities Palette
If a VI running on an RT target uses a subVI from the RT Utilities palette, the VI cannot be mass compiled without errors as long as the project or VI are open during the compile.

Workaround: Close the project and VI and run the mass compile again. It should run successfully.

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016
654235

Return
If 2 classes call separate instances of a polymorphic VI and an instance is included within the a class, the VI will break when compiled into an RTEXE.
A VI will break when compiled into an RTEXE if the VI contains multiple classes that call a polymorphic VI and the a copy of the polymorphic VI is in one of the classes.

Workaround: Add the polymorphic VI to each instance of the class.

Reported Version: 2016    Resolved Version: N/A    Added: 05/19/2018
Miscellaneous
606691

Return
Calibration procedure of Touch Screen Monitor in NI Linux Real-Time Does Not Adapt to Screen Resolution
Running the calibration procedure in something other than the maximum resolution of the touch monitor will cause some of the calibration points to be outside of the visible screen area. Thus the calibration procedure can not be completed and will be aborted.

Workaround: Calibrate with maximum screen resolution orIn an open terminal, type "xinput_calibrator --geometry WxH", where W is the screen width in pixels and H is the screen height in pixels.

Reported Version: 2016    Resolved Version: 2018 SP1    Added: 05/19/2017
Operating System Specific
677278

Return
Directory permissions may change on NI Linux Real-Time when modifying files via WebDAV.
When modifying a directory via WebDAV on NI Linux Real-Time, the directory permissions may change to read-only.

Workaround: Manually change the permissions back to read and write access as necessary.

Reported Version: 2017    Resolved Version: N/A    Added: 05/19/2018
700007

Return
CPU load may be incorrectly reported when using Timed Loops on NI Linux Real-Time
In NI Linux Real-Time, the CPULoadTotal property node may incorrectly report the CPU Load when Timed Loops are used as part of the application.

Workaround: N/A

Reported Version: 2017    Resolved Version: N/A    Added: 06/04/2018
Remote Target
543061

Return
Error 56 Thrown When Using "Disconnect from Slave" Invoke Method
Using the "Disconnect from Slave" invoke method will almost immediately generate error 56; however the method functions correctly and disconnects the NI Real-Time system from the host machine.

Workaround: Ignore error

Reported Version: 2015    Resolved Version: N/A    Added: 03/08/2016

Document last updated on 4/30/2018

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