2.1. Mechanical APDL as a Server Sessions

A Mechanical APDL as a Server session is similar to a conventional Mechanical APDL session, with the addition of an Internet Inter-ORB Protocol (IIOP) interface that accepts connections from suitable client applications. This function is different from batch mode in that commands can be issued to the running session at any time in addition to a predefined file. This allows for solution steering and other manipulation without exiting from the running simulation.

2.1.1. Starting Mechanical APDL in Server Mode

You can start Mechanical APDL in Server Mode in two ways:

In either case, the Mechanical APDL as a Server session generates a keyfile in the session working directory with the information necessary for a client to connect to the session. For more information, see Mechanical APDL as a Server Keyfile and Connecting to Mechanical APDL in Server Mode.

2.1.1.1. Starting Server Mode from the Mechanical APDL Product Launcher

From the Customization/Preferences tab, add -aas to the Additional Parameters.

2.1.1.2. Starting Server Mode from the Command Line

Use the following commands to start Mechanical APDL in server mode:

On Windows platforms:
```
C:\> ansys242 <options> -aas
```
On Linux platforms:
```
> ansys242 <options> -aas
```

These commands assume that the Mechanical APDL executable is refered to in your PATH environment variable.

For more information on command line options in Mechanical APDL, see Starting a Mechanical APDL Session from the Command Level in the Operations Guide.

2.1.2. Mechanical APDL as a Server Keyfile

As described in Starting Mechanical APDL in Server Mode, when you start a Mechanical APDL as a Server session, a keyfile is created in the session working directory that contains the information required for a client application to connect to the session. The keyfile is a text file containing in Interoperable Object Reference (IOR) string that contains information about the host, port number, and protocol for connecting to the Mechanical APDL as a Server session.

You can use the -iorFile keyfilename command line argument to specify the name of the keyfile. If you do not provide this argument, the file is named aas_MapdlID.txt by default.

If a keyfile already exists that refers to a running Mechanical APDL as a Server session, the new Mechanical APDL as a Server session will fail to start. This behavior prevents inadvertently overwriting a keyfile.