I just connected my Xantrex 3.3 inverter to my PC for real-time data capture, it works great. The data is displayed on the PC and also captured in 2 files (one for daily totals, the other every 10 seconds through the day).
I am also hoping to getting a Schulmberger Vectron Net Meter from the Electricity company and hope to track the actual usage from the mains in real time.
http://www.metermansupply.com/products-schlumberger.htm
http://www.southernutility.com/rs232.htm - in Tucson these meters are now meant to be the standard moving forward. I don't know yet whether joe public will be allowed to connect to these meters, as I think maybe the Elec company might not allow or - or they might use the RF connection for their own purposes and the system may not be cable of supporting both a serial and RF connection.
So the benefts are that you monitor both production and usage to cut down on costs by changing how you use electricity. Also due to the kick backs from the Electricity company (TEP) - I have to send in the system kWh each month. Also monitoring the data, you get to "know" the system. I picked up that the Xantrex inverter runs hot (heat sink temp of 151 F on a 80 F ambient temp day, which in theory is above their system specification), but the system is still running at 95% efficiency so it is obvioulsy ok, but in summer when it is 110 F here I will probably have problems with the inverter efficiency being affected. All in all for the captial outlay of buying a serial cable or Cat 5 cable (or wifi/bluetooth) - it is worth doing as you can monitor the efficiency of the solar system and catch problems early etc.
So you have some choices and this site seems to cover them all:
1. Cheapest and most relaible is a serial cable (with DB9 ends) from the inverter to the PC, with the GT View Software. The only complication is that the serial socket does not pass through the casing hole. Better option is to buy 2 RJ45 to serial cable adapters ($3.50 each) and a length of regular straight through Cat 5 cable with RJ45 ends.
2. Bluetooth wireless connection. You will need blue tooth on your PC or laptop, if you don't you can buy a USB bluetooth adapter for your PC from newegg.com for $20 (get Class 2 bluetooth - longer range). I purchased an Air Cable serial to bluetooth device (ACC1302)
http://www.aircable.net/serial.html - follow th e supplied instructinos and it connects right in. You can also simply the whole process by buying pre-configured
http://www.aircable.net/cr-usb-serial-male.html from Aire Cable - you $60 for the PC bluetooth adapter. The 2 problems I ran into were that I had a brick wall in betseen the PC and inverter which caused the buetooth to have an intermittant connection. You also have to use a power supply for the bluetooth device in the inverter (Xantrex should deign to give power to pin 9 on the DB8 connecter in the inverter) - which was a pain since there was no electrical socket close to my inverter.
As a workaround, I used the rj45-serial adapter with Cat 5 cable to get around the wall and close to a power socket, then connected the bluetooth device to one end of the cat 5/rj45/serial adapter and the other end plugged into the inverter. The connection is nor rock solid. The irony in all this is that you now keep your PC on during daylight hours to log the data.
3. Wifi option - I found some WiFi devices that you could use. But they were expensive and you needed power also. Basically you end up having to use some kind of programmable wifi router.
Seems like some people use old laptops to log the data too, and either tranmit the data on through wifi or a remote desktop.
Hope this helps in some way.
Examples of data capture that is saved in ascii format on the pc: dail y log file
Date Time VDC DC Amps MPPT DC Pwr AC Pwr Eff VAC AC Wh HS Tmp Freq Status
12/1/2006 13:46:45 285.4 8.08 286.4 2325 2222 95.57 241.9 10243 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:46:57 286.6 8.03 286.3 2322 2219 95.56 242.2 10253 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:47:09 283.7 8.13 289.3 2322 2219 95.56 241.5 10258 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:47:21 288.9 7.96 288.1 2318 2209 95.3 241.9 10267 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:47:33 287.8 7.98 287.5 2316 2208 95.34 240.5 10272 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:47:45 286.6 8.03 286.7 2316 2212 95.51 241.5 10281 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:47:57 286 8.01 286.4 2313 2206 95.37 240.1 10286 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
12/1/2006 13:48:09 287.8 7.98 286.2 2312 2205 95.37 241.9 10296 134 60 ST:3 STS:0000 0000 0002 92fa FA:00
Daily totals summary file:
Date AC Wh AC Peak W Time Online Lifetime AC Wh
10/16/2006 13608 13608
10/17/2006 14392 10:51:24 28000
10/18/2006 16701 10:47:18 44000
10/19/2006 17882 10:41:51 62000
10/20/2006 17468 10:36:26 80000
10/21/2006 17246 10:36:44 97526
10/22/2006 16945 2016 10:13:31 114472
10/23/2006 10366 10:10:41 124839
10/24/2006 10266 135105
10/25/2006 15687 10:25:45 150792
cheers