Siemens SIMATIC NET PROFIBUS Otdr Evaluation, Otdr provides the measurement results graphically

Testing PROFIBUS

OTDR Evaluation

The OTDR provides the measurement results graphically

Start of fiber

Coupling

End of fiber

Fusion splice

Backscatter

Power ]dB[

Bonding splice

Distance

Figure A-5 Representation of the OTDR Measurement Results

Figure A-5 clearly illustrates that the power of the launched light reduces constantly along the fiber-optic link. There are significant jumps at the coupling points of the fiber.

The following conclusions can be drawn from these results:

SWhether the coupling points should be replaced due to excessive attenuation

SWhether the fiber has been damaged when installing the cable

SThe distance between the impairments and the start of the fiber

Based on this information,

Sdefects resulting from installation can be eliminated,

Sfiber-optic links can be documented in detail and, if problems are occurring, can be compared with the link at the time it was installed (warranty or not).

PROFIBUS Networks SIMATIC NET	A-11
6GK1970-5CA20-0AA1 Release 2 05/2000