Overview

Introduction to the CST solver interface.

This page discusses:

CST is a high performance EM solver for high and low frequency applications that can be used together with Tosca to optimize the shape or topology of EMAG solutions.

Setup

EMAG optimizations with CST are set up in the graphical user interface of the solver and not in the Tosca Structure.gui. With it the user can create the Tosca parameter file (.par) and CST solver inputs (.cst) required to start the optimization. For more detailed information on how this setup is done refer to the CST user assistance.

Execution

The optimization run is started in the usual way with Tosca offering some specific command-line options to control the EM solver execution: --emag_cpus, --emag_gcpus and --emag_threads. If more than one EMAG solvers are configured you can select the target solver by the --emag parameter.

Configuration

Tosca must be given the path to the EMAG solver installation before an optimization can be run. This must be done once per installation but can also be changed individually for each run:

  • To add the CST path to the Tosca installation, the user can add the INS_TSO_CST_PATH=<path-to-CST> parameter to the [Tosca] section of the installation configuration file <install-dir>/SMA/site/EstablishedProductsConfig.ini.
  • It is also possible to set the path to the CST with the environment variable SMA_TSO_CST_PATH. This definition has priority over the installation configurations and can be used to quickly change the solver when starting an optimization.
  • In addition, the tosca.cfg configuration file can be used to declare different versions the same way it is done for the other solvers.