Define a Data Type
==================

.. highlight:: c

To distribute data using |me|, you must first define a data type, then
run the *rtiddsgen* utility. This utility will generate the type-specific 
support code that |me| needs and the code that makes calls to publish 
and subscribe to that data type.

|me| accepts types definitions in Interface Definition Language (IDL) format.

For instance, the HelloWorld examples provided with |me| use this simple
type, which contains a string "msg" with a maximum length of 128 chars: ::

    struct HelloWorld {
           string<128> msg;
    };


For more details, see :doc:`../usersmanual/types` in the *User's Manual*.