My 3 Xantrex GT 3.0 inverters system is up and running for 4 days. (Hurray!).

I am trying to find the best way to gather data from the inverters. From reading Xantrex application notes and manuals, even if I connected the three inverters with Xantrex Bus, I can only get the cumulative daily data of all three using one serial connection to one inverter. In order to get specific data from each inverter, I MUST talk to each inverter's serial port.

Is is possible to query specific inverter data from a single serial connection? That is, if my serial connection is to inverter 1, can I ask it production information from only inverter 2, rather than the 3 inverter cumulative production information?

If the answer is no, then is there any use of linking the inverters via Xantrex bus rather than leaving them disconnected and run a serial cable to each inverter? I can always add the numbers myself for the cumulative results, right?

Thank you for any information on this,
KTT

check out

http://www.xantrex.com/forum/forum_posts.asp?TID=216&PN=1

Short answer is if you want more than system ac watts and system watt-hour data you need to poll each inverter with it's own copy of GT-View and serial port on the PC.

The RS-232 is independant of the Xanbus, and if you want GT-View to report system totals you need them interlinked. The RS232 can only retrive unit detailed data from the unit its physically connected too.

Thanks for the quick response and the thread pointer, Solar Guppy,

I'll run 1 serial line to each inverter, as well as link them with Xanbus. I'll try to find your suggested Edgeport 4 or 8 port serial device, or maybe just another RS232 PCI port card (since I already have 2 ports on the motherboard) for my 3 inverters. I'll connect them with 2 runs of 8-wire CAT5e cabling, using 3 wires for each serial connection.

KTT

A PCI card is one option

If you only need one additional port, this should work

http://www.newegg.com/Product/Product.asp?Item=N82E16812104561

I use and recommend edgeports, on ebay they are $25.00 for 4 port and $35.00 for 8 ports. These are commerical grade, used in the POS industry, new they are 400-600 bucks

http://search.ebay.com/search/search.dll?cgiurl=http%3A%2F%2Fcgi.ebay.com%2Fws%2F&fkr=1&from=R8&satitle=edgeport&category0=

Thanks for the pointers! I just ordered an Edgeport/4 on order from eBay.

It seems to me that the interface between the inverters and the computer really should be isolated to guard against ground loops and especially power surges. Do you have RS-232 opto-isolators in place between your inverters and computer/Edgeport unit, Solar Guppy?

If not, I suppose the Edgeport unit would most likely fry first, before your computer, should a surge go through the serial line... Does Xantrex have a position on this issue?

Also, would you know if it's possible to share signal ground among the Edgeport/4 ports? That is, if I can share one signal ground wire, then one run of 8 conductor cat5e cable would be able to handle all three of my inverters (3 pairs for RX & TX, one conductor for shared signal ground).

Thanks,
KTT

Yes you can share the ground, the Xanbus makes a common ground connection when the GT's are interlinked. The CPU's are isolated from all the inverter electronics internally so from a protection stand point, the RS232's are effectively isolated and no I do not use another level of isolation and never had issues, even in lightning capital of the US here in Florida

I've deployed the Edgeport/4 unit. As per your information, I only made one run of Cat5e cabling, using 2 conductors each for the three inverters. I shorted the remaining two condutors together and used them as signal ground for the three RS-232 wirings. No opto isolations used.

Your GTView program works perfectly.

I would like to try to run this off of my Fedora Linux box. Do you know if there exists a Xantrex GT 3.0 RS-232 command and response description document somewhere? I saw your suggestion to use an RS-232 logger on GTView, and will try that if there are no available specs.

Thanks for your help,
KTT

Question:
Could your software :GT View run on a PDA? I have two GT3.0 inverters and want to be able to monitor both, rather than having a computer running I though I could use a PDA or the sort with the excel client.
This is a cheap device and if the software could run on it I can just tranfer the data via a cradle.

I don't own a PDA and have never tried running GT-View on Windows CE.

As for cost, a old used laptop off of ebay can be had for 100 bucks that is low-power, cheap and will do your data collection needs

The PC need to be connected and running GT-View to log data, the Xantrex GT inverter does not store anything more than current day and lifetime kWr values