Siemens SIMATIC NET PROFIBUS Owner's Manual page 87

Blank form for a power budget using OLMs
Attenuation for the OLM/G11, G12, G11-1300 or G12-1300 for one point-to-point link with wavelength
=
Attenuation on the cable
Fiber type Attenuation
( m ) a in dB/km
FOC
Attenuation of connectors
a (dB) Number
Conn
Attenuation caused by splices
a (dB) Number
Spl
Attenuation of the transmission path
Power that can be coupled
into m fiber
P
out, min
Receiver sensitivity
Prec
, min
(dBm)
Maximum permitted attenuation
Link power margin
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
Cable length L
in km
L* a
Number *
a
Number * a
a
(dBm)
a
a
=
FOC
+
Conn
Spl
=
Path
= P – P
max out, min rec, min
– a =
max Path
Configuring Networks
dB
dB
dB
dB
= dB
dB
3-21