Development and debugging user-written subroutines

This section provides information that is helpful during the development and testing of subroutines.

User written subroutines written in FORTRAN can use any text-editor. If linked into the TMG model through an include file specified within a preprocessor, then the source code file must have the following structure:

  • The first subroutine in the file is USER1.

  • The first line of the file must start with SUBROUTINE USER1.

    Make sure that there are exactly six spaces before the word SUBROUTINE. Alternately the file can start with FUNCTION as long as the USER1 routine appears later.

  • All other user routines must be included in the file.

It is a good idea to compile the routines separately before running the TMG model so that syntax errors can be resolved. This negates the possibility of having a run end because of a compiler error.

Debugging USER1 subroutine using Visual Studio

You can compile USER1 subroutine with the debugger attached. You must use:

  • The DEBUG_USER1=1 environment variable.
  • NX 10 or later version.
  • Correct version of Visual Studio.

To debug, you need to start Simcenter3D/NX session with the debugger attached to the process. There are two USER1 debug modes:

  • USERDLL, when attach to process called analyz.exe.
  • T12.exe scheme, when attach to process called t12.exe.

You have to set any breakpoints to examine your code. This can either be an infinite loop or a pause.

The debugger lets you examine:

  • The values stored in variables.
  • The changes of the values.
  • The execution path of your code.