How to Test the Connection to Your SMA Inverter

This post was originally published in 2016. The tips and techniques explained may be outdated.

You have created your own application for querying SMA inverters via SMA Modbus or SunSpec Modbus. Unfortunately, something does not seem to be working properly and the inverter is not responding as expected.

A Modbus simulator enables you to test the connection to your SMA inverter. Using this tool, you can query the value of a register from your SMA inverter—and if you receive a response, this means that you can rule out the IT environment, for example, as a potential source of the problem.


You can obtain the freeware from the following website:

Modbus Master Simulator

Important: The simulator is not SMA software and we cannot perform any service activities for it.


SMA requirements:
  • Inverter with Speedwire (Ethernet) interface
  • Inverter with Modbus interface


Quick Reference Guide:

1. Set the network address

First, you have to find your inverter’s network IP address. This is the same address where you access the inverter in a web browser or in Sunny Explorer.



Open the tool and choose Connection/Settings or click the icon in the toolbar.


Enter the IP address of the inverter that you want to query.



2. Connect to the inverter

Once you have entered the IP address, connect to the inverter by clicking “Connect.”



3. Create a new file

Once the connection is active, create a new query window.



4. Enter the parameters

Now enter the following parameters:

  1. “Device ID”: 3 (for querying via … 3 – SMA Modbus, 126- SunSpec Modbus)
  2. “Address” (register to be queried; here 30051)
  3. Select “Holding registers” (read and write)

Simulator with SMA documentation

Simulator with SMA documentation


Once you have queried the value of the register, you will receive a response like the one shown above in the sample screenshot.

Register: 30051 (query of device class)

Response: 8001 (output value = Solar inverters)


I hope that this quick reference guide is helpful for you.


    • Leonie Blume
      Leonie Blume says:

      We regret to tell you that Sunny Explorer is designed for Microsoft Windows OS only. The software won´t be able to run on a tablet device.


  1. Avatar
    Max Müller says:

    I have a STP-12000TL-20 and I am trying to communicate with a 485 Interface Data Module Type B, and this method is not working for me.
    There´s something I am doing wrong?
    If so, where can I find instructions to get data through RS485 to my SCADA system?

    • Avatar
      Julia Stunz says:

      Hello Max,
      We regret to tell you that it isn`t possible to have access to the inverter from type STP-12000TL-20 without a data logger/gateway,
      such as the SMA Sunny Webbox or the SMA Cluster Controller. Therefore, data query through RS485 only through your SCADA system won´t work.

      Kind regards,

      • Avatar
        Julia Stunz says:

        Hi Max,
        We would like to suggest that you contact directly the manufacturer of your choice.
        Please kindly understand that we have not tested all available gateway units.
        Therefore, we can not guarantee the functionality of the data logger you have mentioned in your previous message.

        To learn more about the Modbus protocol interface, please follow the link.

        Kind regards,

  2. Avatar
    J Dawson says:

    Sunny portal iOS app crashes when I try to open it. I tried reinstalling, but that didn’t help. Any ideas?

    Thanks, Janet.

    • Avatar
      Julia Stunz says:

      Hi Janet,
      Could you please tell us, which version of the Sunny Portal App do you use?

      Best regards,

  3. Avatar
    Max says:

    Hi, I have an STP-12000TL-20. Does it have a SMA Modbus / SunSpec ModBus Data Interface? Is it different from STP-12000TL-US?

  4. Avatar
    Willy says:

    I’m trying to write to the registers of the Sunspec Profile (unit id 126) of my Sunny Island 3.0M-11 (with SpeedWirte module). In particular I’m writing a ‘1’ to register 40375 to which I’m supposed to have read/write access. This should change the mode of the battery management system to ‘Battery discharge’. I’m getting no Modbus-exception when I do a ‘Write Multiple Registers’ (Modbus function 16)- but reading that register again shows me no change- it still holds a ‘0’.

    Do I have to login as some super user first, to be able to write to registers of the SunSpec profile?
    Is there any other possibility to manually discharge the battery over Modbus TCP?

    Best regards,


  5. Avatar
    Vincent Quintin says:


    Should it work with this model?

    SB 5000TL-21 536
    Firmware: 02.81.01.R
    Communication version:

    I have just tested with the simulator with the parameters given in this article and I get 65565 as value for all addresses (without any error read or write).

    Via Sunny Explorer, modbus is activated (TCP/502+UDP/502) and Unit Id is well set on 3.

    Thanks in advance for your answer.



  6. Avatar
    Rajko says:

    Hello, I have the STP 1000TL10 inverter, with software 02.55.00.N and Speedwire/webconnect module. I am trying to read Modbus TCP data, but all I got is data showing 4294967295 results. I doubt that the software version is correct because I read that it must be, at least, version 2.65.02.R. Where can I find the upgrading firmware software? I took a look on SMA webpage, but unfortunatly I did not find the correct one for my inverter type.

    Best regards!


    • Rhea Terlinden
      Rhea Terlinden says:

      Dear Rajko,

      Since the inverter has been discontinued already, the firmware updates are available at in the download section “Archive”.
      Please read the update instructions carefully in order to install the update.

      Kind regards


  7. Avatar
    Jeroen says:

    I have the Sunny Boy 3600 Smart Energy and I’m using Modbus to charge/discharge the battery.
    When I send the 6 commands for grid management per second, the battery charges/discharges but after 10 seconds the Sunny Home Manager takes over for a short time.

    I changed the time between the commands but that doesn’t help.

    Can someone help me please?

    Best Regards,


    • Carolyn Schlosser
      Carolyn Schlosser says:

      Hello Jeroen,

      Please contact you installer. He knows your system and the local conditions the best. In case he is not able to help you, feel free to sign in on our Service-Line.

      Sunny regards,

      • Avatar
        Sheshbahadur says:

        Hello Carolyn ,
        We have installed SMA Sunny Tripower Solar Inverter Model No : STP25000TL-30 , Serial No : 1901252689.
        Connected the Internet cable on Lan Port A , But Inverter is unable to get IP address and other Information due to this we are unable to view online data, If we remove the cable and connect to Laptop we are able to browse the internet , kindly let us if any setting or configuration need s to activated or deactivated. Router is on DHCP . Could you guide us what is the problem

  8. Avatar
    Jeff Unabia says:

    We installed an Inverter Manager and a Janitza meter for the zero export function.
    We already configured the details on the “Limited Export” tab of the LCS tool.
    Is there other configurations that we need to do to assure that there will be a zero export?
    We got advised that we need to access Sunspec Modbus and set register 19026 to zero,

  9. Avatar
    eduard de jong says:

    We have 3 sunny tripower invertors. What material is needed to get them connected to a scada systemen and communicate with Modbus TCP.

    Do we need a cluster controller or can we connect directly. Is there any detailed information how to get connected (a system topology)?

    • Avatar
      Nick Samson says:

      Hi Eduard,
      we need to know which device designation and which firmware your inverters have?
      best greetings

      • Avatar
        Eduard de Jong says:

        Hi Nick,

        We hebben met de Sunny Explorer de Modbus op ENABLE gezet. We krijgen echter steeds xFFFF terug als antwoord. Het modbus ID hebben we op 1,2,3,126 gezet maar niks veranderd het antwoord. Onze units zijn 2110337101, 2110337640 en 2110383319.

  10. Avatar
    Chiellio says:

    Hallo Eduard de Jong,
    Wij hebben hetzelfde probleem!. Hebben jullie al een oplossing aangedragen gekregen, zoja mogen wij dit ook weten?.
    Alvast bedankt.

  11. Avatar
    Brillian Rolduz M. Teope says:

    Hello, we have the sunny boy 7000-us inverter with the RS485 piggy back module, may i know what are the following modbus profile:

    Baud Rate:
    Data bits:
    Stop bits:
    Flow control:

    • Anke Baars
      Anke Baars says:

      Hi Brillian,
      I´m sorry, but Sunny Boy 7000-US has no Modbus interface. The RS485 module is for communication with a datalogger, e.g. WebBox. The inverter is not in our portfolio anymore.
      There are also different old and new types of SB 7000 US:
      – SB 7000 TL-US-22: has no Modbus interface, the RS485 module is for communication with a datalogger, e.g. WebBox. Inverter is also not in our portfolio anymore.
      – SB 7.0-1XP-US-40: has a Modbus/TCP interface via the Webconnect module, Modbus/RTU via RS485 is not implemented. The RS485 interface is for the SMA Revenue Grade Meter Kit.
      Either the old inverter have no Modbus overall, or the new inverter has Modbus/TCP.
      I hope, this is helpful for you.
      Kind regards, Anke

  12. Avatar
    Brillian Rolduz M. Teope says:

    Hello Anke Baars, what are the options to have our SCADA (Wonderware) communicate with the SB7000US?

  13. Avatar
    Brillian Rolduz M. Teope says:

    By the model of inverter we have is the spr-7000m which i assume is the same with the sb7000us

  14. Avatar
    Billy says:


    I’ve tried to make a modbus communication with my Sunny Boy SB2.5-1VL-40 (FW 2.5.1.R) , I successfuly get it work when using Device ID 3 (SMA Modbus).
    But I didn’t succeed to use the Device ID 126 (SunSpec Modbus). Is it normal?

    • Anke Baars
      Anke Baars says:

      Hello Billy,

      To read or to write Modbus registers in each case use register numbers reduced by the offset of 1. Example:
      Modbus register address = Modbus register number in SunSpec Modbus profile – offset
      40001 – 1 = 40000.
      Please find further information concerning Modbus® and SunSpec®Modbus®.
      Kind regards,

      • Avatar
        Billy says:


        thanks for the response.
        Unfortunately, I didn’t succeed to use Mobus Doctor with Device ID 126 as I get a timeout when requesting data (address 40001 for example) . It only works with Device ID 3 (address 30051 for ex).

        On other side, I succeed to ran pySunSpec with Device ID 126 and the returned data are relevant. But I do not know which address this software is requesting. Seems there are still some things I do not understand 🙁

  15. Avatar
    Gachoud Philippe says:

    as answered for the 12000TL, does the 10000TL have a modbus sunspec compliant interface without any data logger like cluster controller?

    • Anke Baars
      Anke Baars says:

      Hi Gachoud,
      All inverters of type STP 10000 have a modbus sunspec interface. To use sunspec modbus, the inverters have to be equipped with the Speedwire data module. Please also bear in mind that the minimum firmware versions have to be installed on the devices (please refer to the technical information SunSpec Modbus Interface document to see which firmware versions are supported and their corresponding device-specific Modbus registers).
      All documents can be downloaded at in the download area. If you are not able to find your type directly on the download section, please check the menu archive that is also found in the download area of our website.
      I hope this is helpful for you.
      Kind regards, Anke

  16. Avatar
    Kemas says:


    I have SMA Sunny Island SI8.0h-12 but I have some problem with modbus configuration. I can’t do “modbus command” to create set point power active and reactive nevertheless it is OK just for reading meter data by using modbus. Do you know how to configure modbus communication? Do you have experience with set point Power active using Modbus ?

    • Anke Baars
      Anke Baars says:

      Hi Kemas,
      Thanks for your request. I´ll send you an email with the relevant information. Just check you inbox and let me know if it works.
      Kind regards,

  17. Avatar
    Syaiful says:


    I have Sunny Island SI 3.0 with included SWDMSI-NR10 for communication, It still use SRC for setting the parameter, but we can’t access the SI to turn on MODBUS enable, so our controller still cant read the SI.


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