Wireless or cable?
Secure connection with and without wire
To monitor solar power systems, data has to be transmitted. For example, 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. Here, you can discover which method of communication best suits your solar power system.
A comparison of the two systems
| Bluetooth (radio) | RS485 wiring | |
| Typical application | Especially for small and mid-sized solar power systems | For medium and large solar power systems |
| 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 m in open air between individual devices |
1200 meters per RS485 bus |
| Data retrieval devices (for example, Sunny Beam or Sunny WebBox) |
Up to four per network (depending on number of participants) | One per RS485 bus |
Wireless Success – intelligently connected 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-plaster or paint. Therefore perfectly suited to your private home rooftop system. Bluetooth, the international wireless standard, makes your monitoring flexible and extendable. You save time and installation costs. Thanks to Bluetooth, all new inverters are recognized in a flash and automatically integrated into the system. Due to intelligent networking, up to 50 devices can be integrated in a network. Because Bluetooth Class 1 is used, large distances between the devices are possible. And if that should ever not be enough, for example if walls or ceilings are in the way, the SMA Bluetooth Repeater can be used. Bluetooth also stands up in terms of reliability. Thanks to constant frequency changes and the transmission of data packets in small units, the radio connection is extremely stable. And the broadcast power is always adapted to the particular requirement. By the way: the password protection built in to all devices secures your data against unauthorized access.
Robust and secure – powerful across long distances with proven RS485 wiring
RS485 is a classic in the area of communication technology. This wired variant has been used by SMA for many years and has proven itself in countless systems. All devices are simply connected in a chain (a so-called data bus). At the end of this chain, the Sunny WebBox collects all the data and reliably on the status of the solar power system.
The advantage of RS485 wiring: functional lengths of up to 1,200 meters and reliable data transmission even in interference-prone areas. Because with larger solar power systems in particular, you require maximum security and reliability.
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