SMA SI 3324 Installation - Manual (Page 53)

SMA Technologie AG Electrical Connection
Installation Guide SI3324/4248-14:SE2406 Page 53
5.4.6 Synchronization
These connections are intended as synchronization connections for possible future
communication systems and are not presently used.
Do not connect anything to these terminals.
Connection Function
S_IN - synchronization INPUT, negative
S_OUT - synchronization OUTPUT, negative
S_IN + synchronization INPUT, positive
S_OUT + synchronization OUTPUT, positive