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solar 1kw installation; inverter rs232port

Discussion in 'Hobby Electronics' started by tuppy, Apr 20, 2009.

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  1. tuppy

    tuppy Guest

    Many people (like myself) are installing 1kw grid tie inverter systems
    to take advantage of rebate system. I am happy with it except the
    solar installer doesnt have technical knowledge about interfacing to
    the rs232 port on the inverter for data logging etc. The inverter is
    a generic rebadged brand so cant contact manufacturer. cms-2000

    I am wondering if anyone has played with the serial port of their grid
    tie. What baud rate? Can you use hyperterminal that comes with xp.
    What command do you send to it?
  2. terryc

    terryc Guest

    Who did you use?
    nope, but there are two general problems; wiring, then settings.

    If you have never connected anything else to your serial port, you are on
    a steep learning curve.

    What wiring depends on what the ports on each end are. It depends if is
    DTE or DCE on the solar boxen, whether you need a straight through or
    crossover(null modem) cable.

    Basically, there are null modem cables and null modem cables.

    Then is depends on protocol, 9600, 8,N,1,P was common.

    Practical steps, get a null modem cale and join them together. Load
    hyperterminal, config for direct and above and tape the keys.

    Try Xon/xoff forst over hardwire(?)

    If you get garbage, especially a good strong string(menu?), then wiring
    is generally okay and it is just a matter of protocol settings.

    This sort of stuff is why I keep a couple of serial terminals around.
    Save fighting terminal programs(hyper,mnicom,etc) to sort out basics.
  3. Eeyore

    Eeyore Guest

    You mean stealing other peoples' tax money. You should be ashamed of
    yourself. Solar thermal is vastly better.

    PV is a JOKE.

  4. Franc Zabkar

    Franc Zabkar Guest

    You can tell which pins are outputs by looking for +/-12V. Inputs will
    probably be floating.

    - Franc Zabkar
  5. terryc

    terryc Guest

    With that attitude, I hope you have not accepted any government super co-
  6. Franc Zabkar

    Franc Zabkar Guest

    CMS2.0 kW Grid PV-Inverter Installation and Operation Manual Version
    2.5 E 2008.07: 0Kw Installation and operation manual 2_5E_update(07-06-08).pdf

    The RS232 port is a DB9 connector with only 3 pins being used, TxD
    (2), RxD (3), and Common (5).

    Page 29 of the manual states ...

    2. Optional communications port: This port is a very powerful
    extension. Inverter can accept a special card designed for the port
    only. The RS485 card is used to work with Inverter’s EZ logger and in
    multiple monitoring applications. CMS plan to release other
    communication cards in the near future.

    3. Firmware upgrade: To keep the firmware up to-date, use the RS232
    port and supplied program to upgrade firmware.

    - Franc Zabkar
  7. Franc Zabkar

    Franc Zabkar Guest

    I suspect that the manufacturer may be Phoenixtec. They claim to be
    the leading UPS maker in Taiwan. In fact if you search for phrases
    from the CMS manual, you will find Phoenixtec Sunville manuals with
    the same phrases, especially in the troubleshooting section, and with
    the same typos and identical Chinglish.

    See the indoor unit on page 3 of this brochure:

    Here is a brochure for their EZ logger:

    The CMS-2000 could be a Phoenixtec indoor model PV-2000X or similar.

    - Franc Zabkar
  8. terryc

    terryc Guest

    Do they even know? I thought these were incompatible standards?
  9. Franc Zabkar

    Franc Zabkar Guest

    Hmmm. The EZ logger has both interfaces, although its RS232 port
    appears to be used for modem hookups. It looks like the logger is
    meant to be installed indoors and connected to the inverter via an
    RS485 run. RS485 is optional for the inverter, but standard for the

    BTW, I just received a quote via telephone. Aussie Solar use Google
    Earth to view your house. They can determine an optimum location for
    your panels, and can even suggest where to put your inverter. I reckon
    I will see payback within 5 years, or maybe even 3, if the NSW
    government increases the buy-back tariff for power returned to the
    grid. At the very least it should increase the value of your home, or
    your estate.

    I can't locate where I read this, but it appears that the inverter
    shuts down when mains power is lost to prevent power being fed into
    the grid when linesmen could be working on it.

    - Franc Zabkar
  10. MisterE

    MisterE Guest

    Its a disgrace what the goverment is doing. Giving $8k to families who earn
    under $100k so they can put in 1kw is absolutely rediculous. The difference
    once you go from $99,999 to $100,001 is stupid. A 1kw system typically costs
    $12k, but only $4k on the rebate.. a 66.6% discount, thats rediculous. The
    people who earn over $100k have to pay 3 times as much, not to mention that
    its their taxes paying for the other people anyway.

    What the goverment doesn't understand is that the price of panels are largly
    set by the price of existing electricity. WIthout the repayment its about 20
    years until it pays off, most studies show solar panels aren't even carbon
    neutral until 15 years, 30 years if the water used to make them comes from
    de-sal. They are just a joke - like water tanks.
  11. terryc

    terryc Guest

    any credibility you had went out the window with that statement. It is a
    well known fact that the more people earn, the less tax they pay in this
    country, unless they are total fools. Ergo, Big Kezza having a taxable
    income of $17,000 one year.
  12. Franc Zabkar

    Franc Zabkar Guest

    The rebate system is due to change very soon. AIUI, after next month
    everyone will get a non-means-tested $5K rebate or credit. Of course
    this means that, after next month, *nobody* will find it economical to
    install a PV system.

    As of this moment, each PV installation comes with 21 Renewable Energy
    Credits. Aussie Solar offer to buy these from you for $1K. I don't
    know whether these will still be available after the Budget. In fact I
    am having a lot of trouble determining their actual market value, or
    finding a way to sell them on the open market.

    - Franc Zabkar
  13. terryc

    terryc Guest

    Err, so if I do it now, I get $4k, but if I wait I can get $5k
    and if Aussie solar do it, I can sell the Energy Credits for $1,000 extra?
    (what is the catch?)
  14. Franc Zabkar

    Franc Zabkar Guest

    It doesn't matter who supplies the equipment. AIUI, any renewable
    energy "project" is assessed for its eligibility for carbon credits. A
    1kW PV project is worth 21MWh over some defined life span, and this
    equates to 21 RECs. These credits can be traded, or offset against
    one's carbon generating activities.

    - Franc Zabkar
  15. KR

    KR Guest

    I wouldn't buy them for "carbon" purposes - the whole AGW scam is just
    a crock of bullshit anyway.

    The panels could be useful for emergency power - once the state
    governments/greenies and the economic crisis inevitably run the
    electrical (and every other) infrastructure into the ground and we
    have constant daily blackouts / shortages.

    For example, a 1kw unit could run a small refrigerator for several
    hours a day, and charge batteries for running modest lighting / small
    TV / laptop and ADSL box etc in the evening.

    A generator would be needed as backup though, but to fuel the thing
    all day wouldn't be cheap. The solar system would probably save money
    in generator fuel ?

    Agree on the tank theory too. since the average household supposedly
    uses 1 kl per day, ( 1 kl = $1 on our local water rates) and the
    suggested tank capacity (local council building regulations for all
    new homes) is 5000L, the tank holds $5 of water - or 5 days with
    normal family use.

    If it rained enough every 5 days to fill the thing, then you would
    save your entire water rate charge, ($365 a year based on above
    figures). in 10 years you might have the cost of your tank and its
    related pump / plumbing repaid - not counting interest etc.

    In a normal world - where we currently live right now - where there
    is 24h water and electricity, both of these items are financially

    In a future world where we are screwed with carbon taxes etc, it might
    be a different story
  16. Franc Zabkar

    Franc Zabkar Guest

    The following document may provide a clue. It is for a UPS RS232
    interface, but maybe some commands are similar.

    Phoenixtec UPS Communication Protocol:

    For example, you could try the ID (UPS ID enquiry) command, or Q
    (Status Inquiry), or Q1 (Status Inquiry - typically used by CheckUPS),
    or T (test).

    Another way is to obtain a firmware upgrade and look for text strings
    in the image file.

    - Franc Zabkar
  17. Brexant


    Oct 24, 2009
    Invertor RS232

    I came upon this thread looking for information on the serial port on this invertor. Obviously the thread has gone way off topic.

    What I do know is that the inverter is fitted with a RS232 card that can operate over 30 metres. Optionally a RS422 port card can be fitted to run a theoretical distance of hundreds of metres. There is a monitoring & configuration software that the installers use to test and program.

    Interfacing and working out the query strings should be fairly easy. By the way it is a standard RS232 with no fancy stuff. The wiring pinouts can be found in the manual. It does not state the baud rate but I would guess it would be 9600. Flow control is probably xon/xoff. This could be found by trial and error.

    If one can get hold of the monitor program and get that running properly it should be easy to monitor the data with another terminal and find what queries to send to get it to send out the data we want for monitoring. If the designers have been kind, the serial port will be sending this data every 10 seconds and all we need to to is capture and process the data.

    I hope this is the start of someone having a go at working out a simple monitor.

    Anyone who feels the need to pour their (often ill informed) opinions here can take a walk to somewhere else. It is this kind of attitude that will hamper development of sustainable systems. Every watt of electricity put into the grid helps us to reduce our reliance on fossil fuels. For the ill informed, it takes around 5-8 years to repay the energy used to produce the PV cells and this is decreasing each year. As far as I can work out it is certainly well worth doing.
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