Siemens SIMATIC NET PROFIBUS - Manual (Page 87)

Configuring Networks
3-21
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
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
λ
=
Attenuation on the cable
Fiber type
(
µ
m )
Attenuation
a
FOC
in dB/km
Cable length L
in km
L* a
FOC
= dB
Attenuation of connectors
a
Conn
(dB) Number +
Number *
a
Conn
dB
Attenuation caused by splices
a
Spl
(dB) Number
Number * a
Spl
dB
Attenuation of the transmission path a
Path
= dB
Power that can be coupled
into
µ
m fiber
P
out, min
(dBm)
Receiver sensitivity
Prec
, min
(dBm)
Maximum permitted attenuation a
max
= P
out, min
– P
rec, min
= dB
Link power margin a
max
– a
Path
= dB