SMA SIC 50 - Manual (Page 28)

Electrical Connection SMA Solar Technology AG
28 SIC50-IA-en-11 Installation Guide
6.6.4 Stand-alone Operation
Up to 8 charge controllers can be connected to each other. Connect the MSTE bus input of the charge
controller with the MSTE bus output of the following charge controller. Use an RJ45 cable for this.
Pin Assignment of the MSTE Bus
Pin Function Level Description
4 GND 0 V reference potential
3 TXD bus / RXD bus TTL, open collector resting potential: +5 V
active: 0 V
9 Shield, protective earth