Archived: LabVIEW 8.6.1 Control Design and Simulation Module Known Issues
Updated Mar 17, 2020
NI does not actively maintain this document.
This content provides support for older products and technology, so you may notice outdated links or obsolete information about operating systems or other relevant products.
This document contains the LabVIEW 8.6.1 Control Design and Simulation Module known issues that were discovered before and since the release of the LabVIEW 8.6.1 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.
The following sections describe known issues at the time of the LabVIEW 8.6.1 Control Design and Simulation Module release.
Cannot use Simulation Loop or subsystems in ARM
The Simulation Loop and simulation subsystems are not supported in the LabVIEW Embedded Module for ARM Microcontrollers.
Trim and Linearize functions might hang VxWorks targets
The SIM Trim and SIM Linearize VIs generate an exception on VxWorks targets and might cause the targets to stop responding.
Workaround—Trim or linearize the model on the host machine, then deploy the resulting model to the VxWorks target.
Upgrading to the Control Design and Simulation Module 8.6 might change SISO functions to MIMO
Upgrading VIs from earlier versions of the Control Design and Simulation Module to version 8.6 might change SISO functions to MIMO functions. This issue affects only functions that use the Control Design state-space, transfer function, or zero-pole-gain data types and that have indirect feedback.
Workaround—Delete the wire connected to the input u(k) input of the first indirect function in the feedback loop. Wire a scalar double value to the input u(k) input. The scalar double data type propagates through the feedback loop. Delete the wire connecting the scalar double value to the input u(k) input and recreate the first wire you deleted.
Configuring MIMO model from input terminal of Discrete Zero-Pole-Gain function generates error
In the MIMO instance of the Discrete Zero-Pole-Gain function, if you configure the Zeros-Poles-Gain model using an input terminal instead of the configuration dialog box, LabVIEW returns error –2326 when you run the simulation.
Workaround—In the MIMO instance of the Discrete Zero-Pole-Gain function, select the Zeros-Poles-Gain parameter to configure the options for that parameter. Then select Configuration Dialog Box from the Parameter source drop-down menu to configure the zero-pole-gain model in the configuration dialog box. If you must configure the model during run-time, for example to simulate a linear time-variant system, use the Model Conversion VIs to convert the zero-pole-gain model to state-space or transfer function form, then wire the resulting model to either the Discrete State-Space or Discrete Transfer Function function.
Built applications containing subsystems with control design models might crash on embedded targets
Built applications on embedded targets might crash if they contain a state-space, transfer function, or zero-pole-gain model output of a Control Design VI wired to the model input of any of the following Simulation functions:
Discrete Transfer Function
Workaround—Use the CD Convert Control Design to Simulation VI to convert the state-space, transfer function, or zero-pole-gain control design model to a model you can use for simulation. Then rebuild the application and deploy it to the embedded target.
Vector instance of Discrete Integrator function might return incorrect results if number of inputs does not equal number of initial conditions
The Vector instance of the Discrete Integrator function might return incorrect results if you set discrete integrator to backward or trapezoidal and the number of elements in the input array does not equal the number of elements in the initial condition array.
Workaround—Ensure the number of elements in the input array equals the number of elements in the initial condition array.