A2W Wireless Controller Master Units Omron Automation A2W Wireless Controller Master Units perform master-slave wireless communications with A2W Wireless Pushbutton Switches using the sub-GHz band. This is realized by sending ON/OFF data from the pushbuttons to the Master Unit and responding to reception confirmation to the pushbuttons from the Master Unit. Manufacturing sites require more versatile and flexible production systems due to the frequent changeover of low-volume production. These controller master units support multiple switches/connections (up to 8) with a focus on decentralized control. The A2W wireless pushbutton switches and controller master units use a 922.5MHz frequency band to reduce interference and provide a better signal in locations with obstacles.