All of Maestro devices support RS-485 serial using a Modbus communications protocol.
The RS-485 physical layer allows long transmission distances, high electrical noise immunity, and flexible connection in a linear or multi-drop mode to any PLC, SCADA, DCS or control system.
The Maestro device acts as a slave in a four-wire, half duplex mode on a Modbus network. This arrangement fully supports bi-directional communication of data and diagnostic functions on any Maestro device.
Modbus is a fully open protocol that is simple, robust and has become a global de facto standard of connecting industrial electronic devices.