This section describes the basic process for developing a Definition File for Post.
This section pertains to:
Recommended procedure for developing a Definition File
Inheritance of Definition Files
When creating a Definition File for Post, it is not necessary to start building from an empty file. There are a number of Definition File templates for you to use as a starting point when creating a Definition File for your specific machine tool.
Start by selecting the Definition File template with characteristics that most closely match the characteristics of the machine that you are creating the new Definition File for. The Definition File templates that are provided contain "commonly used" formats for Format, Address and Block Template statements.
Review the Format statements contained in the Definition File template and make sure that there is an appropriate Format statement to cover all the data formats required by your machine controller. You will need to create a Format statement for any situation that is not already included in the template.
You will also need to review all the ADDRESS statements included in the template and, using the existing ones as a guide, add any additional ones that may be needed by your machine controller. You also need to review the Format, data ranges and other data associated with each existing ADDRESS statement to make sure that they meet the requirements of your controller. Modify each existing ADDRESS statement as necessary.
Finally, review all the BLOCK_TEMPLATE statements included in the Definition File template and, using the existing ones as a guide, add any additional block templates that may be needed by your controller. You also need to review the contents and structure of each existing BLOCK_TEMPLATE command to make sure that it meets the requirements of your machine controller. Modify each existing BLOCK_TEMPLATE as necessary.
When developing your Definition File, you can include one or more existing Definition files. Post will use the statements contained in the inherited files unless they are redefined in the current Definition File, in which case the the inherited statements will be overridden. To develop your Definition Files use the "INCLUDE <file name>" command.
In the case where multiple Definition files are inherited , a statement in the second inherited file will override a statement with the same name in the first inherited file. Likewise, the statements in a third inherited file will override the statements in the second and so on. Finally, a statement in the current Definition File will override all statements with the same name contained in any of the inherited files.
Using this capability will allow you to quickly and easily develop Definition Files for similar postprocessors. By inheriting the Format, ADDRESS, and BLOCK_TEMPLATE statements from existing definition files, you only need to define modified, or additional, statements in the Definition File that you are developing to account for the differences.
A similar capability exists for inheriting existing Event Handler files in the Event Handler that you are developing. For more information, refer to Inheritance of Event Handler Files.