On Load Tap Changer with the Voltage Regulator Control 

The RWT-20 Voltage Regulator Control front panel makes data collection and control quick and efficient. Use the front panel to analyze operating information, view and change device settings, and perform control functions. The RWT-20 features a straightforward menu-driven control structure presented on the front-panel liquid crystal display (LCD). Front-panel LED indicators provide a fast means of checking operation status. You can perform often-used control actions rapidly by using the large direct-action pushbuttons.
  
Distribution Automation Ready. Interface with either on-the-fly settings changes over DNP, or master controller direct-operate interface.

1) Flexible Communications. Easily interface with your network with the
Industry's most network connectable regulator controller.

2) Programmable Without a Laptop. Connect a USB flash drive to
upload new settings, upgrade firmware, retrieve existing settings, or
retrieve reports from the SEL-2431.

3) Expandable, Removable Memory. Connect a USB flash drive and
enable Automatic Backup to write all common reports to the USB for
long-term storage and easy retrieval.

4) IEEE C37.118 Synchro phasor Protocol. Identify connected phase of
downstream voltage regulators by coordinating with sychrophasor
measurements in the substation.