Monitoring PV energy generation, consumption, import and export

Since 2013 we have a photovoltaic system with 5.2kWp on our houses roof. In combination with the SMA inverter it was not a big deal to monitor the PV output. There is a webpage of SMA where you can see the outputs for every day, month and year. The inverter itself sends the data to the SMA servers.

Now I wanted to montitor and visualize all the data by myself. And not only the PV output but also the energy consumption. Which means additionally power import and export. To get these data I installed the SMA Energy Meter. With this piece of hardware you are able to monitor the energy flow for every phase in your house. The measured values are then broadcasted, or better multicasted, to your local lan.

I wrote a little programm to receive these multicasts, extract the interesting values and save them in a SQLite database. Additionally I used the SBFSpot tool to get the current PV output from the inverter. The current PV output will also be saved in a SQLite DB. A small webpage collect all the data from the database and visualize them with Highcharts.

Here are some screenshots of the beta version. It also runs quite fast on a Rasperry Pi 2, but currently I use it on Ubuntu 14.04 LTS.

PV Output, Energy Export and Import.
PV Output, Energy Export and Import.
PV Output, Energy Export and Import.
PV Output, Energy Export and Import (Zoom in/Extract)
PV Output only
PV Output only

Shuttle DS57U Network Performance Tests with iperf

Did some network performance tests with my new Shuttle DS57U. I installed the actual IP Fire 2.17 Core Update 89 on a 16GB SDHC Card, connected the Intel i211 NIC to internal (green) interface and the Intel i218LM NIC to the external, red Interface. I also started the OpenVPN Server on the external Interface. Here are the results…

1st test. Plain routing:

iperf -c -w 256k -l 256k -P2
Client connecting to, TCP port 5001
TCP window size: 256 KByte
[ 4] local port 52004 connected with port 5001
[ 3] local port 52003 connected with port 5001
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-10.0 sec 562 MBytes 471 Mbits/sec
[ 3] 0.0-10.0 sec 562 MBytes 471 Mbits/sec
[SUM] 0.0-10.0 sec 1.10 GBytes 941 Mbits/sec

2nd test. Download an ISO image from internet. Proxy and URL filter (ad, adv) were active:

DS57U bwm-ng download

DS57U htop download

30MB/s…this is limited to my 250 MBit/s Internet connection :-/

3rd test. OpenVPN Performance:

iperf -c -w 256k -l 256k -t 60
Client connecting to, TCP port 5001
TCP window size: 256 KByte
[ 3] local port 54497 connected with port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-60.1 sec 648 MBytes 90.6 Mbits/sec

DS57U htop OpenVPN

More Tests (with different Window Sizes, power consumption etc.) and more Screenshots can be found here.

proFTPd – 530 Login incorrect

If you get an 530 Login incorrect when trying to login to your newly installed proFTP Server, then you should check the following:

  • Did you use the „adduser“ dialog to create your FTP user (instead of useradd -p)
  • Did you configure a „RequireValidShell off“ at the end of your proftpd.conf file?
  • LDAP, PEAP, Cisco ACS and BYOD

    BYOD, LDAP and PEAP is a nice combo. Trying to implement this was a little bit tricky. Here are some hints:
    1. If you use an LDAP like OpenLDAP oder Lotus Notes LDAP, then you must use PEAP-GTC as authentication protocol. MSChap won’t work!
    2. With an Apple iOS you cannot configure which phase2 authentication method you want to use. So, if you enable MSChap AND GTC on your ACS, then the iOS Device will use MSChap. This will result in an authentication reject. Disable MSChap authentication protocol on the Cisco ACS to get these devices working because then the iOS Device uses GTC.
    3. Windows 7 has no native GTC support. If you want to authenticate against an OpenLDAP account database, you must install a 3rd party supplicant. If you have an Intel Wireless Card in your Laptop, you can use the Wireless Utilities downloadable on the Intel Website. After installing these Utilities, you can use GTC as an authentication method.
    4. If you get a lot „EAP timeout“ errors in your ACS Logfile, try to change the EAP Timeout Value in the Wireless Settings (i.e. on the WLAN Controller) from 2sec (Default) to 10sec.

    Cloudstation in DSM4.2 with Active Directory Integration

    I tested Cloudstation on my Synology DS212+ last week. But without AD Integration it was not usefull for me. So I installed latest 4.2 Beta and noticed, that you can also add Active Directory users. In 4.1 you are limited to internal users. Thats really great news for a lot of people out there using a Synology NAS in their company.

    Cisco Secure ACS % Repository not found

    If you are wondering about an error message like „Repository not found“ while trying to patch a Cisco Secure ACS System, just check if the replication status of the ACS Instance is in „updated“ and not in „pending“ or „unknown“. You can only apply a patch if the instance is in „updated“ state.

    acs-1/admin# show repository FTP
    % Repository not found

    Cisco ACS