MotionSolve and Simulink Co-simulation Prerequisites

A few settings are needed to successfully run a co-simulation using MATLAB/Simulink. These steps can be performed in any order that is convenient. In other words, they don't have any dependencies.

In the model, create the plant inputs and outputs from the model to the other (for example, Simulink) model.
1. The inputs should be applied using PINVAL() or VARVAL() (for example, to define forces from Simulink).
  Note: The arguments that need to be specified for PINVAL() are different from the ones for VARVAL(). Please refer to the Reference Guide for details on the syntax.
2. The outputs should use functions that provide values to Simulink (for example, DZ() for displacements).
In the environment that will run MATLAB/Simulink, set the environment variables needed by to be called from the other simulation software (for example, Simulink).
In MATLAB, set the search path for MATLAB/Simulink to find the S-Function library in the installation that is required for co-simulation.
In the Simulink model used for co-simulation, add an S-Function block that represents the model, and enter the proper arguments for the S-Function.

Plant Inputs and Outputs

Create one or more Control_PlantInput and Control_PlantOuput that stores a list of the input and output variables that are passed between MotionSolve and Simulink.
For more details, see those statements in the MotionSolve Reference Guide.
The input variables from Control_PlantInput can be accessed via a PINVAL() or VARVAL() function, and the output variables from Control_PlantOutput are usually runtime functions (for example, DZ(), for displacement) going to Simulink.
Create the number Control_PlantInput's and Control_PlantOutput's in a manner that is convenient to you.
The S-Function that represents the MotionSolve model will update accordingly.
The order of the Control_PlantInput's and Control_PlantOutput's found in the MotionSolve model (.xml) (by line number, from top to bottom) should match the order of the inputs to and outputs from the S-Function.

Set Up Environment Variables to run MotionSolve from MATLAB/Simulink

A few environment variables are needed for successfully running a co-simulation using MATLAB. These can be set using one of the following:

Control Panel (Windows)
In the shell/command window that calls MATLAB (for example, with the set command on Windows)
Within MATLAB, via the setenv() command

Set the environment variables to point to the solver binaries.
NUSOL_DLL_DIR <installation directory>\hwsolvers\motionsolve\bin\<platform>
where <installation directory> is the full path to the HyperWorks installation. <platform> is win64 for 64-bit Windows, and so on.
For example, on Windows 64-bit:
```
set NUSOL_DLL_DIR=C:\<installation_directory>\hwsolvers\motionsolve\bin\win64
```
Set the environment variables for licensing:
RADFLEX_PATH <installation directory>\hwsolvers\common\bin\<platform>
PATH <installation directory>\hwsolvers\common\bin\<platform>;%PATH%

(Notice that the HyperWorks directory is pre-pended to the original PATH).

Note that other optional environment variables may be set for your model. See MotionSolve Environment Variables for more information on these environment variables.

Set the Search Path for MATLAB/Simulink

The core feature in Simulink that creates the co-simulation is an S-Function (System Function) block in Simulink. This block requires an S-Function library (a dynamically loaded library) to define its behavior. MotionSolve provides this library, but the S-Function needs to be able to find it. To help MATLAB/Simulink find the S-Function, you need to add the location of the S-Function to the list of paths that MATLAB/Simulink uses in order to search for libraries.

The S-Function libraries for co-simulation with MotionSolve are called either:

mscosim - for IPC communication

mscosimipc - for IPC (TCP/IP sockets) communication

Changing the name of this library in the S-Function block in Simulink changes the communication behavior of the co-simulation.

These files are installed under <installation directory>\hwsolvers\motionsolve\bin\<platform>.

The location of these files needs to be added to the search path of MATLAB for the S-Function to use mscosim or mscosimipc.

This can be done in one of the following ways:

Use the menu options:
1. From the MATLAB menu, select File > Set Path.
2. From the dialog box, add the directory where the mscosim and mscosimipc DLLs reside.
  For example, C:\Program Files\Altair\2020.1\hwsolvers\motionsolve\bin\win64
3. Select Save > Close.
  This procedure permanently adds this directory to the MATLAB/Simulink search path.
Use MATLAB commands:
1. At the MATLAB command line, type: addpath('<installation directory>\hwsolvers\motionsolve\bin\<platform>') to add the directory where the mscosim mex DLL resides into the MATLAB search path.
  It remains valid until you exit MATLAB.
  Note: You can also create a .m script to make this process more easily repeatable.
  For example, you can set the MATLAB Path and the necessary environment variables using MATLAB commands in a MATLAB (.m) script:
  addpath('C:\Program Files\Altair\12.0\hwsolvers\motionsolve\bin\win64') setenv('NUSOL_DLL_DIR','C:\Program Files\Altair\12.0\hwsolvers\motionsolve\bin\win64') setenv('RADFLEX_PATH',['C:\Program Files\Altair\12.0\hwsolvers\common\bin\win64') setenv('PATH',['C:\Program Files\Altair\12.0\hwsolvers\common\bin\win64;' getenv('PATH')])

Add the S-Function Block for Simulink that Calls MotionSolve

An S-Function (system-function) block can be found in the Simulink User-Defined Functions block library. An S-Function allows you to model any general system of equations with inputs, outputs, states, and so on, and is somewhat analogous to a Control_StateEqn in MotionSolve. See the MATLAB/Simulink documentation for more details.

After creating it, you will need to enter the arguments described in MotionView S-Function in Simulink Arguments.

For an example of this process, see the tutorial MV-7002: Co-simulation with Simulink.