Siemens SIMATIC NET PROFIBUS manual Blank form for a power budget using OLMs

Configuring Networks

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	Attenuation	Cable length L
( ∝ m )	aFOC in dB/km	in km
			L* aFOC =
Attenuation of connectors
aConn (dB)	Number	+
			Number *
			aConn

dB

dB

Attenuation caused by splices

aSpl (dB) Number

Attenuation of the transmission path

Power that can be coupled

into	∝ m fiber
		Pout, min (dBm)

Receiver sensitivity

Prec, min (dBm)

Maximum permitted attenuation

Link power margin

Number * aSpl

aPath =

amax = Pout, min – Prec, min =

amax – aPath =

dB

dB

dB

dB

PROFIBUS Networks SIMATIC NET	3-21
6GK1970-5CA20-0AA1 Release 2 05/2000