FeABPLC

The software is based on the library libplctag from github.com (https: //github.com /libplctag /libplctag). It is an open source code that can be uploaded and used in other projects. The library was used in a .dll file and it was adapted to work with a DDE server.

The tags in FeABPLC program are used for DDE communication. FeABPLC is a DDE Server with the default settings: DDE Application = “AB”, DDE Topic = “TAGS” and DDE Item = “TagName”, where “TagName” is the name of any tag defined by the user.

The user can define a list of PLCs IP addresses to conect with. For every PLC different tags can be assigned. The tags can be: integer, float, or string. Every tag has two names: the DDE name (e.g. Temperature) and the PLC name (e.g. N7:40).

The program can handle different PLC connections and quite a few number of tags per PLC. More than that, if a PLC connection is lost, the program can wait until the connection is reestablished. Extensive testing was done with PLC5, SLC500, Micrologix, CompactLogix and ControlLogix AB PLCs to read, write, or read/write tags. Apart of integers, floating numbers and string tags were tested.