To run FieldConvert in parallel the user needs to compile Nektar++ with MPI support and can employ the following command
mpirun -np <nprocs> FieldConvert --npt <nprocs> test.xml \ in/test_<n>.fld out/test_<n>.vtu
mpirun -np <nprocs> FieldConvert --npt <nprocs> test.xml \ in/test_<n>.fld out/test_<n>.dat
replacing <nprocs> with the number of processors and <n> by the starting time index while
the subdirectories in and out are optional. FieldConvert will then process in parallel time
solutions test_<n>.dat to test_<n>+<nprocs>.dat.