Allen Bradley
Allen Bradley is a large player in the industrial automation scene. Siemens is their only real competitor in this regard. They have a wide variety of products in various model lines and their products is typically where the vast majority of PLC programmers first get a taste of PLC programming. Since they are so widespread there is good support and documentation for them. Their proprietary development software is predominantly RSLogix which includes 500 and 5000. RSLogix 5000 being very powerful with some very nice functions that should be included in all development environments if you ask me. It is pricey though...anywho, here are their current product lines: ControlLogix - Large Scale: "Our ControlLogix® control systems use a common control engine with a common development environment to provide high performance in an easy-to-use environment. Tight integration between the programming software, controller, and I/O modules reduces development time and co...