What are the buttons on the left side of the RMU referred to as?

The correct designation for the buttons on the left side of the RMU is "Field select keys." These keys are specifically designed to allow the user to select data fields for various purposes, such as updating settings or navigating through different options on the RMU display. Their primary function is to interact with specific fields on the screen, making them essential for the efficient operation and customization of the system.

In contrast, control keys would typically refer to buttons that perform general commands or actions rather than field-specific tasks. Function keys generally provide pre-defined functions but are not specific to field selection, while navigation keys are associated with moving through menus or options rather than selecting specific data fields. Understanding the exact role of the field select keys is crucial for effectively managing the RMU's functionalities during operation.