Unitronics designs, manufactures and markets quality PLCs for the global market.

Easy to use, efficient, and affordable, Unitronics? products have been automating processes and stand-alone applications since 1989.

Unitronics? OPLC? controller series integrate PLCs and built-in operating panels into a single compact device. This unique PLC + HMI concept saves wiring, I/O points, and programming time.

Micro PLCs with expandable I/O and easy-to-use Ladder Builder software. Other functions include frequency counter, ramp-up/down controls, and more. Industry's first Programmable Logic Controller with a built-in data window for real time monitoring and changing of program parameters.

Popular Japanese company offering PLC among many other devices for automation control. The United States Omron web site is easier to navigate.

Major Japanese manufacturer of PLCs and other automation equipment.

If you are looking for support then go to the Mitsubishi Electric Automation site 

The original PLC owned now by the Schneider Group.

A leading European electrical and electronics firm offering a wide range of automation controls. Good luck on their website as I have a hard time finding what I need. You may have more luck at the Automation and Drives section.

A diverse selection of controllers, I/O, and programming tools - easy to integrate and expandable with powerful functionality and durability and able to support multiple platforms and third party interfaces.

Large manufacturer of power, control and information systems and services.

Red Lion Controls has built a strong reputation in several product areas including human machine interface, process measurement and control, and digital measurement and control.

AutomationDirect is a direct seller of automation and industrial control products such as PLCs, sensors, pushbuttons, AC drives/motors, enclosures, operator interfaces, and much more.