PROFIBUS OLM/P11 Optical Link Module with 1 x RS-485 and 1 x plastic FO interface, with signaling contact and measurement output

his is part of PROFIBUS Networks SIMATIC NET described in manual 6GK1970-5CA20-0AA

Integrated Optical Interfaces, OBT, OLM The optical version of SIMATIC NET PROFIBUS is implemented with integrated, optical ports, optical bus terminals (OBT) and optical link modules (OLM).

Duplex fiber-optic cables are used as the medium made of glass, PCF or plastic fibers. Duplex fiber-optic cables consist of two conducting fibers surrounded by a common jacket to form a cable.

Modules with integrated optical ports and optical bus terminals (OBTs) can be interconnected to form optical networks only with a bus structure.

Using OLMs, optical networks can be installed using a bus, star and ring structure. The ring structure provides a redundant signal transmission path and represents the basis for networks with high availability.

With glass fibers up to 15,000 m dependent on the fiber and OLM type
With plastic fibers: 
OLM: 0 m to 80 m 
OBT: 1 m to 50 m

Siemens Teleperm XP (T2000)