Siemens ESM - Manual (Page 24)

Introduction
Industrial Ethernet OSM/ESM
20 C79000-Z8976-C068-10
Properties of the OSM BC08
Ports 8 x 100 Mbps FO ports (full duplex)
BFOC female connectors
Maximum distance between two OSMs 3000 m (multimode graded-index fiber)
Maximum ring span with 50 OSMs 150 km
Digital Inputs 8 x DC 24V