Wired or Wireless

Secure connection with and without cable

To monitor solar power systems, data has to be transmitted. This can be power values or energy yields. For the communication between the solar inverter and monitoring devices, SMA provides two basic choices: wireless and wired variants. Both have advantages and are used with different sized systems. Let SMA help you decide which method of communication best suits your PV plant.

A comparison of the two systems

  Bluetooth
(radio connection)		 RS485 wiring
Typical application Especially for small and mid-sized solar power plants For mid-sized and large solar power plants
Advantages Reduced costs and effort High speed and reliability
Number of participants
(system monitoring and inverters)		 Up to 50 per Bluetooth network Up to 50 per RS485 bus
Range Up to 100 meters in the open airbetween individual devices 1,200 meters per RS485 bus
Number of data retrieval devices
(for example, Sunny Beam or Sunny WebBox)		 Up to four per network One per RS485 bus

Wireless Success - intelligently networked with SMA Bluetooth

With SMA Bluetooth, wireless networks can be created simply and quickly - without the additional effort of having to lay cables in walls, re-plastering or painting, making it perfectly suited to your residential rooftop system. Bluetooth, the international wireless standard, makes monitoring flexible and extendable. Installers and plant operators save time and installation costs. Thanks to Bluetooth, all new inverters are recognized quickly and automatically integrated into the system. With the SMA intelligent networking concept, up to 50 devices can be integrated in a network. Bluetooth Class 1 is the standard used and it enables communication over longer distances. If that’s not enough because walls or ceilings are in the way, you can also use the SMA Bluetooth Repeater to strengthen the signal and extend the range.

Bluetooth is also reliable. Thanks to the transmission of data packets in small units and constant frequency changes, the radio connection is extremely stable. The broadcast power is also adapted to meet the connection’s specific requirements. Built-in password protection secures your data against unauthorized access.

Robust and Secure - powerful across long distances with proven RS485 wiring

The RS485 fieldbus is a veteran in the area of cable-connected communication technology. It has been used by SMA for many years and has proven itself in a nearly endless number of systems. All devices are connected to each other in a chain (i.e. a data bus). At the end of this chain, the Sunny WebBox collects all the data and reliably informs you of the status of the PV system. The advantage of RS485 wiring is that functional lengths of up to 1200 m (3937 ft) and reliable data transmission can be achieved even in interference-prone areas. It is also appropriate for larger solar power systems, where operators require maximum security and reliability.