## 18.2. User Junction Box Routines

In addition to defining your own CEL functions, you can call user subroutines at several points during execution of the CFX-Solver; such subroutines are called junction boxes. Junction boxes can be used to accomplish a number of different tasks:

- Input / Output of user data.

- Advanced solution monitoring tasks.

- Coupling of CFX with other software packages.

- Program control (for example, control of the termination criteria of coefficient loops in a transient run by some other means than maximum number of iterations or residual targets).

User defined junction box routines are passed only to the CFX-Solver workspace stacks as arguments. Unlike user CEL functions, there are no user arguments for these routines. However, by using the CFX MMS (Memory Management System) utilities, advanced users have full access to the internal data structures of the CFX-Solver. For details, see CFX Memory Management System (MMS). Some simplified routines have been implemented to enable access to commonly used data in the MMS. For details, see Utility Routines for User Functions.

CEL variables are not available for use in junction box routines.

You can call more than one junction box during a run.

Release 18.2 - © ANSYS, Inc. All rights reserved.