[Linux-aus] Photovoltaic inverter monitoring or logging software

[Kevin Maciunas]

On 02/02/14 17:45, Bret Busby wrote:
>
> Hello.
>
> In the research that I had done, I found the following.
>
> The software that was supplied with the (3000TL) inverter, is JFY
> Inverter Communicator v1.1, which apparently, from the
> screenshots in the included (PDF) manual, is for MS Windows XP. The
> manual file is dated November 2012.
>
> At
> http://forums.whirlpool.net.au/archive/2060578
> is shown that either rewiring of the RS232 port, is required, or, use of
> the inverter manufacturer supplied RS232 cable is required. The manual
> indicates that an RS232 cable as supplied by the inverter manufacturer,
> should be used, but one was not supplied when the unit was installed.
> The electrical contractor that installed the PV system, had said that I
> should be able to get a standard RS232 cable from an electrical
> accessories supplier. However, it needs a special cable.
>
> I need to chase that one up, to find whether I can obtain the required
> RS232 cables from the company that installed the PV system.
Just looking at the quoted thread - the cable looks far from "special".  
RS232 is designed to connect Data Terminal Equipment (ie the computer) 
to Data Communications Equipment (ie a modem).  In this situation you 
have two DTE's - so you need a cross over cable. So Rx-->Tx and Tx-->Rx 
so the two ends can talk to eachother. You should be able to get a cross 
over cable from anywhere.
> I have never done anything like reverse engineering software, but that
> sounds horrifically complicated to me.
>
> The forum thread URL in the message above, appears to refer to those
> blackberry pudding things (from the messages in the thread... "I have
> one in the meterbox", were they supplied with the photovoltaic
> systems, as part of the photovoltaic systems mentioned?), and the
> software being written for the blackberry puddings, and so appears to be
> not in Debian Linux packaging.
>
>
Raspberry Pi is just a small single board computer that runs Linux. 
There are lots of Pi like things out there, but I suspect you could just 
walk up to the inverter, plug in a cross over cable to your 
laptop/desktop/whatever and run a "terminal emulator" program.  You will 
need to set the comms link to 9600bps, 8bit, no parity, 1 stop bit 
(9600N81) and you'll just see the data come up on the screen. It works 
like that for the Kaco inverter I have :)

So for me the logging (for one day, with the laptop perched on bricks :) 
) is done by:

cat /dev/ttyACM0 > logfile

And yes, it really is that simple.
One day I might build a logger into a DB9 backshell that powers itself 
from the RS232 port and logs it to an SD card, but I have my one day of 
typical behaviour and it was enough for me!

Hope this helps
/Kevin

-- 
Kevin J. Maciunas              Net: kevin at cs.adelaide.edu.au
Dept. of Computer Science      Ph : +61 8 8313 5845
University of Adelaide         Fax: +61 8 8313 4366
Adelaide 5005 SOUTH AUSTRALIA  Web: http://www.cs.adelaide.edu.au/~kevin
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