SMA Sunny Data Control V.5.0 - Manual (Page 21)

Connecting the PC to a Communication Device SMA Technologie AG
Technical Description SDC-TEN081450 23
5.2. 2 Connection via RS485
RS485 communication characteristics:
• Up to 50 Sunny Boy Control / Plus devices can be connected to a PC.
• The PC must be equipped with an RS485 port. If it is not, please read section 5. 1 "Notes on
the Use of Level Converters" (Page 20).
• Each Sunny Boy Control requires an RS485 Piggy-Back at the PC (COM 2) port.
Alternatively, at the Sunny Boy Control Plus, the AUX (COM 3) port can be used, if this is
equipped with an RS485 Piggy-Back.
• The maximum total cable length is 1200 m.
Cabling Recommendations
The cable length and quality affect the signal quality. Observe the following indications in order to
achieve good signal quality.
• Use metallic D-Sub female connectors. Female connectors made of plastic, or metallized
plastic, can cause faulty data transfer.
• For the outdoors, use a communications cable with the following important properties.
- Cross-section: At least 2 x 2 x 0,22 mm
2
, and at least 2 x 2 x AWG 24
- shielded
- Twisted pair cables
- UV resistant
We recommend the following cable types for the outdoors.
SMA communications cable: COMCAB-OUTxxx*
*Available in the following lengths: xxx = 100 m/200 m/500 m and 1000
Lappkabel cables: UNITRONIC Li2YCYv 2 x 2 x 0.22 mm
2
You can use an indoor cable for the outdoors as well, provided you protect it from UV
radiation with the proper cable duct.
RS485