Siemens SIMATIC NET PROFIBUS Owner's Manual page 85

Power budget for OLM/G11, G12 for a point-to-point link with the wavelength
= 860 nm
Attenuation on the cable
Fiber type Attenuation
a
FOC
62.5/125 m 3.5 dB/km
Attenuation for connectors
a Number
Conn
0.4 dB 1
Attenuation caused by splices
a Number
Spl
0.2 dB 3
Attenuation of the transmission path
Characteristic data of the OLM/G11, G12
maximum power coupled into 62.5/125 m fiber
P
out, min
–13 dBm
Receiver sensitivity
Prec
, min
–28 dBm
Maximum permitted attenuation
Link power margin
The transmission path can be implemented as planned.
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
Cable length L
2.85 km L* a =
FOC
Number *
a
Conn
Number * a
a =
Path
a = P
max
a – a
max Path
Configuring Networks
+
+
+
Spl
– P =
out, min rec, min
=
10.0 dB
0.4 dB
0.6 dB
11.0 dB
15.0 dB
4.0 dB
3-19