Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

Gliffy Diagram
nameApi Change - Chris Copy
pagePin1619

General

  • I ensured all of our classes have the "Plc" prefix, as I did encounter situations in which very generic type names had collisions and I had to use the fully qualified class name (including the package name). The "Plc" prefix reduces this risk.
  • Introduced a PlcFieldRequest / Response classes, allowing PlcRequests and Responses that don't use field information (When calling functions, for example)
  • Removed the "RequestItems". Now the data for the plc read responses is contained in the PlcReadResponse/PlcWriteRequest itself.
  • Added the concept of a named-field which is in general a Field description combined with a string alias.
  • All sub-types of the PlcFieldRequest/Response use these aliases to reference the field they want to access. Resulting in an API that is more similar to JDBCs RecordSet.

...

  • The getObject() is a convenience method to return values of the natural type determined by the field definition itself. This is the smallest possible type fit to contain the PLC type.
  • The setObject() is a convenience method. Actually thinking about it a little bit more, we might even have just the setObject version and get rid of the rest.
  • A "typeConverter" is passed in by each driver, that handles the encoding/decoding of values for that particular driver.

Example Code

Here comes some example code to demonstrate how a Programm using this API could look like.

...