1. Bluetooth® NetID: the electronic picket fence

With the SMA Bluetooth wireless communications standard, solutions for system monitoring are especially easy to realize. This is because devices compatible with Bluetooth are easy to network, independently and rapidly, to form a reliable wireless network. In order to separate systems which are adjacent to each other, however, first you must establish a standardized network ID (NetID) for all inverters within one system. All inverters with the same Net ID then form a common wireless network.

Simply configured, simply connected

At the inverter, you set the NetID using a small rotary switch, which can be turned using a screwdriver (Figs. 1 and 2). The numbers from 2 to 9 are available, as are the letters from A to F, that is, 14 different values. The NetID "0" is used to turn off the Bluetooth functionality, with the 1 (factory setting) the inverter establishes a maximum of two data connections to computers with the Sunny Explorer software. The query devices (e.g., Sunny Beam with Bluetooth, computer with Sunny Explorer or the forthcoming Sunny WebBox with Bluetooth) are not set manually, but rather, they adopt the NetID of the inverters within range. If available, the different NetIDs from which to choose are listed. Since you should disconnect the inverters completely (on the DC and AC sides) after a change of NetID and must restart them afterwards, you should check for the presence of other Bluetooth networks before commissioning. To do this, use one of the query devices mentioned above.

2. Sunny Beam: which rechargeable battery should I use?

The mobile Sunny Beam yield display is also forward-looking when it comes to energy supply: by means of the solar cells the integrated accumulators are always charged when there is light available – that is, the Sunny Beam is independent from the power outlet. Should there be a need for a change of accumulators, however, you must take into account the different types of accumulator. In standard Sunny Beams, RAM-cells are used. The Sunny Beam equipped with Bluetooth, on the other hand, uses state-of-the-art NiMH accumulators of the "LSD" type, with a similarly reduced self-discharge. One must not confuse these two, because they have different cell voltages and also because they are charged differently. Both have the form of AA cells (mignon).

3. Sunny WebBox: sending data via mobile cellular wireless

When you use the Sunny WebBox with GSM module, you can transmit the plant data independently from a classic telephone or data line. You only need a GSM cellular network with a strong enough signal where the Sunny WebBox is located. For a successful configuration, two things must be observed, however: upon commissioning the GSM module you must always use as a dialing number for the data connection the "99***1#", mentioned in the manual (this is valid for all service providers). The asterisks are not variables representing random numbers, they are necessary command symbols. Please also note that the antenna included is always screwed on, – even when you are not intending to use the GSM module (Fig. 3). Otherwise it could happen that the Sunny WebBox does not start, or that the network connection is interrupted at irregular intervals.

Important detail: the termination resistor

You must make sure that the bus cable is terminated on both ends with termination resistors. In the case of Sunny Mini Central inverters, older Sunny Boy series and the Sunny WebBox, the termination resistor on each device can be enabled or disabeld: using jumpers, small plugged bridges which are connected at corresponding poles on the circuit board and which function as switches. In the case of inverters, the termination resistor is disconnected at the factory (no jumper) whereas it is connected at the factory in the case of the Sunny WebBox. In case of inverters of the new generation (e.g., Sunny Boy 5000 TL or Sunny Tripower) and of the Sunny SensorBox, a real termination resistor is connected between the terminals D+ and D– of the output side, which you have to remove, if required (Fig. 5).