I am in the process of installing the RS485N comm. between my 3 2500U, soon to be 2500 SunnyBoy inverters. Tired of walking out and getting numbers, let the program do it. But the install instructions from SunnyBoy is terrible. They do not even call out what signals are on the pins, trial and error, no way to run a business. Pin in the inverter is gnd, so leaves 2 left for A and B on differential pair. 50/50 I get it right the first time. Has anybody done this. Even their tech support did not know. Installing the module is pretty straight forward, but the cable hookup leaves something to be desired.

On 3 wire RS285, pin 1 is usually DATA-, pin 2 is DATA+ and pin 3 is GND.

I was talking about the connections inside the SunnyBoy itself. I know the connection points, see tech updates on their web page, problem is they are identified. Conn. 5 is gnd. The other 2 are hit and miss. Thanks for replying though. RS485 is not that hard, I just thought maybe somebody has done this before. Apparently SMA has not here in the USA.

Sorry, I meant pins are not identified. Guess Ishould have re-read the post before submitting.

Dan :

It looks like th e following gives you a good glimpse for how to wire your PC running SunnyData up to the SB communications adapter : http://www.sma-america.com/ftp/Com%20RS485%20to%20SBC%20Tech%20Note%20V14.pdf

Even tho this is for the SBC (SunnyBoy Control), there looks like enough info here to determine the connections on the SB adapter card:
terminal 5 = GND
terminal 3 = Rs485+
terminal 7 = Rs485-

It appears for regular RS-232 they just mimic the pinouts found on a DB-9:
pin2 = Tx
pin3 = Rx
pin7 = GND

Guys, lemme know if I got this right

-- Larry H