Also Energy’s PowerTrack device monitors solar-electric generation; whole-house and branch-circuit demand; and solar thermal systems; with accurate energy cost calculations (see “Independent Options” sidebar). It offers three models of weather station and can connect to SMA America inverters and any Modbus RS-485-compatible inverter (see below) and meter. The PowerLobby device is an option for performance display on a kiosk.
Modbus is an industrial-control data protocol that has been adopted by many commercial solar-monitoring devices, such as AC meters, weather stations, inverters (for status codes and power readings), and DC string current monitoring devices. RS-485 is a serial cable wire similar to the common RS-232 computer standard, but allows for up to 32 devices on a cable up to 4,000 feet long.
