The ddi file preparation is performed using the ddi.exe utility. For more details on how to work with it, see The ddi.exe utility for editing database templates and external settings files.

To create the ddi file for the objects of the CUSTOM and CUSTOM_CHILD types, use the following order:

1. Run the ddi.exe utility (see The ddi.exe utility for editing database templates and external settings file).
2. Create two CUSTOM and CUSTOM_CHILD objects on the DDI tab, as shown in the figure below.
   
3. Go to the Events tab and configure the events that must be supported by the object (see the figure).
   

4. Go to the Reactions tab and configure reactions that must be supported by the object (see the figure).

   Reactions of custom objects are automatically converted into events. In other words, the custom object automatically generates the corresponding event if the reaction occurs.

   

5. Go to the States tab and describe the states that the object can take. Here there are two states—ON and OFF.
   

   In the Image column, you can specify the postfix of the file name located in the <Axxon PSIM installation directory>\Bmp folder. For example, the custom_off.bmp and custom_on.bmp files corresponding to the ON and OFF states are for the CUSTOM object. These files are used by the Map module.

6. Go to the Transfer rules tab and configure the object state change logic.
   
   State transfer rules is a simple state machine where an event is the input action and the state is a result.
   In this particular example the unconditional transfer is used: if the CUSTOM||ON event comes, it transfers to the ON state, if the CUSTOM||OFF event comes, it transfers to the OFF state.
7. Save changes using the Save command in the File menu. The saved file must have the ddi extension and must be located in the folder corresponding to the required language, for example, C:\Program Files (x86)\Axxon PSIM\Languages\en\psim.custom.ddi.

The ddi file preparation is complete.