PLC Software

In the late 1980s when PLCs were first being adopted, both Allen Bradley and Modicon had dedicated terminals for program development. These tools had special keyboards and simple screens. They could be connected to the PLCs for Ladder Diagram development and loading. They could also be connected to printers for documenting the programs.
At that time, they were all we had, and the available features were quite limited. In particular it was not possible to include comments or headings, or cut and paste repeat program sections.
Several independent companies developed PC based software tools that could not only duplicate the system supplier's terminals, but added powerful extra features. One such company was Taylor Industrial Software from Edmonton in Canada. Another was Xcel Controls.
Taylor were one of the first and most successful third party companies providing PC based programming software for various PLCs. They had packages for Allen Bradley and Modicon, and I think Square D. When they got started the PLC guys were making a lot of money selling separate programming consoles and cassette loaders for each PLC model in there product line. Taylor came up with a PC based package that was much better than the cassette loaders, and was much better than the early PC programming packages from the PLC manufacturers themselves. Eventually, either through purchasing third party packages like ICOM and Taylor, or through internal development, the PLC companies caught up, and the independents disappeared.
One of Taylor's main product lines (ProWorx Plus, ProWorx NXT) for Modicon programming was purchased by Schneider Electric’s Automation Business in May 1999.

Modicon: The first PC Based. ProWORX
Modicon: PC Based. ProWORX NxT
Modicon: PC Based. Updoc
Modicon: PC Based. Modsoft
Modicon: The first Windows Based. ProWORX NxT
Modicon: Windows Based. ProWORX 32
Modicon: The Next Windows Based. Concept
Modicon: Windows Based. Unity