This section describes command line arguments that System Coupling solver provides to the participant solvers. This section is not relevant for mapping-only workflows.

System Coupling starts participant solvers as child processes during the setup stage and at the beginning of a coupled analysis. Therefore, the participant participant executable will need to be provided to System Coupling. See System Coupling User's Guide for more details.

It is highly recommended to create a wrapper script (either batch script, shell script, or any other kind of script) around actual participant executable. This script can parse the arguments provided by System Coupling and set any environment variables, as needed.

Coupling-Specific Command Line Arguments

The following command line arguments are provided by System Coupling:

• --schost HOSTNAME : name of the host where System Coupling is running. This value should be passed in as input into the participant library function that establishes the connection with System Coupling.
• --scport PORTNUMBER : port number on which System Coupling is listening for incoming connections from the participant solvers. This value should be passed in as input into the participant library function that establishes the connection with System Coupling.
• --scname PARTICIPANTNAME : unique name for this participant, given by System Coupling. This value should be passed in as input into the participant library function that establishes the connection with System Coupling.
• --scsetup : This argument is used to indicate the the participant should be started in the setup mode.
• --screstart RESTART_STRING : This command line argument is only used during a restart run. The provided string is used to tell the participant solver which restart point to use. This string is provided from participant solver to System Coupling during a previous run. See Creating Restart Points and Restarting the Coupled Analysis for more details.

For example, the following execution command may be generated by System Coupling:

Parallel Execution-Specific Command Line Arguments

For a coupled analysis, System Coupling typically allocates available computing resources to each participant. For a participant that uses the the participant library, System Coupling will pass available computing resources via a command-line argument when starting this participant.

See Execution in a Parallel Environment for more details.

Local Parallel Execution

To enable local parallel execution, the following command-line argument will be passed to the participant:

-np NPROCS

Here, NPROCS is replaced with the number of processes. For example, if the participant solver is to be executed on a local machine using four processes, the command-line argument will be as follows:

-np 4

Distributed Parallel Execution

To enable distributed parallel execution, the following command-line argument will be passed to the participant:

-hostlist HOSTLIST

Here, HOSTLIST is replaced with the comma-separated list of machines and number of cores available on that machine. The machine name and core count are separated by a colon. For example, if there are two machines available named hostA and hostB, and each machine has four cores available, then the command-line argument will be as follows:

-hostlist hostA:4,hostB:4

Note that on Windows platform, quotes are added around HOSTLIST, so that all hosts are provided in a single command line argument.

-hostlist "hostA:4,hostB:4"

Other Command Line Arguments

If other command line arguments need to be passed to the participant solver, this can be accomplished by adding those arguments in the ExecutionControl.AdditionalArguments parameter in the System Coupling datamodel. For example, the following snippet sets the custom command line argument for participant DEFAULT-1 in the System Coupling script:

For more information on the data model structure, see System Coupling User's Guide.