March 2010

A matter of attitude (2)

Practical knowledge of SMA plant communication

As data logger, the Sunny WebBox is the link between the RS485 field bus and the local computer network - and naturally the Internet. It records the yield, operation and measurement data of all inverters and sensors and on request transfers this automatically to Sunny Portal. With this powerful online plant monitoring and visualization tool, the data is able to be viewed via the Internet from almost every location in the world. Essential for the manifold functions of the Sunny WebBox: the correct configuration - from the IP address to date and time. For this reason, the second part of our series deals exclusively with the configuration of the Sunny WebBox.

Why the IP address is important

The function of the so-called IP address of a network device can be compared to that of your telephone number or your mailing address. Only when the address is correct and unique it is possible for mail to reach the recipient. Additionally, in computer networks it is decisive that a new IP address is entered into the available system seamlessly and is never allocated twice. The IP address consists of four numbers between 0 and 255, which are usually separated by a dot. For example, the pre-configured IP address of the Sunny WebBox is 192.168.0.168.

Initial contact ...

As a rule, the pre-configured IP address of the Sunny WebBox must therefore be changed and adjusted to the existing configuration of the customer's network. The only prerequisite: for this, an already functioning network is necessary. This is because as with almost all modern network devices, the complete configuration of the Sunny WebBox takes place via a web interface - that is to say per network via a configuration website. However, this network connection only functions correctly when the network settings are correct.

Abb. 1: Im Zweiernetzwerk mit gekreuztem Kabel - Erstkonfiguration der Sunny WebBox

... network settings

The solution is however very simple: one creates a mini-network for the initial connection with the Sunny WebBox out of just two devices (individual computer + Sunny WebBox), best of all with a network-independent notebook (fig. 1). This is because the IP address and the respective sub-net mask of the computer must be temporarily adjusted where necessary in order that it matches with the pre-configured Sunny WebBox IP address. Important: the IP addresses must have the same first three groups of numbers, but the fourth group must differ. The sub-net masks must be identical. With the notebook IP address 192.168.0.100 and the sub-net mask 255.255.255.0 for example, communication should work. Another important information: since two network devices should be connected directly to one another here, a crossover cable must be used for the connection - for example the blue cable enclosed. The Sunny WebBox can now be accessed using the notebook's internet browser. To do this, simply enter the pre-configured IP address in the address bar, and then the web interface should appear.
After logging in, all Sunny WebBox settings can be changed in order that they match the conditions of the local computer network (fig. 2). Next you must unplug the Sunny WebBox and disconnect the cable connection to the configuration computer. Before rebooting you just need to link the Sunny WebBox into the local network by using a standard patch cable (such as the supplied red cable) to connect it to the router or any network distribution unit. After rebooting, the Sunny WebBox can be accessed by every computer in the network via its new IP address. Further settings are therefore possible.

Abb. 2: Wichtige Nummer - die IP-Adresse der Sunny WebBox

The time must be correct

The correct setting of date and time should definitely be controlled during the initial commissioning of the the Sunny WebBox. Otherwise it could be that the data received from the inverters is recorded with an incorrect time-stamp. Meaningless data would be the result - in the worst case the daily maximum yield would appear to be achieved in the middle of the night. The time stamp cannot be subsequently altered. This means that such data can't be used expediently any more. An incorrect date would also lead to incorrect evaluation and presentation of the yield data in Sunny Portal. Additionally, data records which according to the date stamp are older than 90 days can no longer be processed by Sunny Portal. If you use Sunny Portal, it is therefore absolutely sensible to choose the menu point "automatic time synchronization". In this case, date and time will automatically be synchronized with Sunny Portal each time data is transferred. You should also activate the automatic change from summer to winter time.

The perfect team: Sunny WebBox and Sunny Portal

Important e-mail address for Sunny Portal

For the initial data transfer to Sunny Portal you must perform certain settings. The e-mail address to be entered into the "operator e-mail" field is especially important: the access data for Sunny Portal will be sent to this address, once the Sunny WebBox is successfully registered (fig. 3). Ensure therefore that you have access to this e-mail address. If you already monitor other PV plants via Sunny Portal, it is recommended that you always enter the same e-mail address in the Sunny WebBox. Thus, after logging into the Portal you receive an overview list with the yields of all PV plants.
For security reasons, the Sunny Portal checks the plant identifier and the operator e-mail when a Sunny WebBox wants to deliver data. Only when the identifier matches and also the e-Mail address is listed as user with the status "installer" or "plant administrator" Sunny Portal will allow the data import. Should the e-mail address in the WebBox be altered afterwards, it is imperative that it is firstly registered in Sunny Portal. Theoretically, unlimited numbers of WebBox devices can be assigned to a Sunny Portal plant. In order integrate the data of all WebBoxes, you must enter the same e-mail address and the same plant identifier for all devices.
Tip: if your customers would like to be entered as plant administrator in the WebBox, you should ask him to enter your e-mail address in Sunny Portal as additional user with the "Installer" or "Administrator" role. Many installers who administer and monitor several plants in Sunny Portal have set up a separate e-mail address for this purpose (e.g. SunnyPortal@mycomany.com).

Abb. 3: Sunny Portal lässt grüßen - Betreiber-E-Mail und Anlagenkennung

Everything from the start: the new identity

Sunny Portal differentiates between the individual PV plants and assigns the yield data correspondingly by means of the plant identifier (see fig. 3). In certain cases it may be necessary to change the pre-configured identifier in the Sunny WebBox: for example when replacing the Sunny WebBox or for the integration of previously separated plants or plant components into one Sunny Portal plant. If you use the identifier of an existing plant in Sunny Portal, all data collected from the Sunny WebBox will also be assigned to this plant in the future. You receive automatically a new plant identifier and therefore also a new plant in Sunny Portal with the Sunny WebBox reset - with this however, all of the remaining device settings will be reset.

Forecast

In the third part of this series, we will be taking a look at the "supreme discipline" in plant monitoring: remote access and remote maintenance via the Internet.
Information: you can read the first part of this series here.