User`s guide

Release 7.5 MADYMO Coupling Manual
8.2.6 Argument Interface
When madymo_cpl calls exec2 to start both solvers, a standard argument list is passed to the
PARTNER solver. Of course not all PARTNER solvers are started in the same way. This means
a wrapper script will have to be written, as intermediate layer; the ’febin’ option should be set
to point to this wrapper script. The wrapper script is started from exec2 with this command:
<febin> -nrproc <npfe> -input <feinput> <feargs>
The wrapper script will have to parse these arguments into a valid command to actually start
the PARTNER solver and/or MPIRUN. If HP-MPI is used, the PARTNER solver wrapper script
is started in an environment where a variable FEMPIRUN is set; FEMPIRUN points to the
’mpirun’ executable, with a number of options:
FEMPIRUN = "<mpirun> -spawn -prot -nameserver <nameserver> [-hostfile <PARTNER hostfile>]"
The wrapper script then has to extend the FEMPIRUN variable with exports for the PARTNER
solver (like license variables, LD_LIBRARY_PATH, etc), other desired HP- MPI arguments, the
PARTNER solver executable, and the ’feargs’ string.
Example wrapper scripts for LS-Dyna, MPP-Dyna, PAMCrash, and RADIOSS are given in
Sec.
8.2.9.
8.2.7 Checklist and Example
These are the steps to start a MADCL coupled run:
• Write or obtain a wrapper script for the PARTNER solver
• When using HP-MPI, set the MPIRUN environment variable
• When using HP-MPI and multiple hosts are available, write a host file
• If needed/desired, write a configuration file
As an example, a madymo_cpl command could look like this:
<madymo bin dir>/madymo_cpl -febin <script dir>/cpl_partner.sh \
-npmad 4 -npfe 28 -coupling mpi -mpilib hpmpi \
-hostfile myhostfile -madargs <madymo args> -- \
-feargs <partner args> -- <xml deck> <partner deck>
Now madymo_cpl will:
• Use MADYMO executable in "<madymo bin dir>"
• Use "<script dir>/cpl_partner.sh" as PARTNER wrapper script
44