Siemens SCALANCE X-300 Series

Media module Fiber-optic cable type Max. permitted
cable length
Attenuation
MM991-2P
(SC RJ)
980/1000
plastic optical fiber
50 m 9 dB max. permitted FO cable attenuation with 3 dB link power
margin
200/230
polymer cladded fiber
100 m 6 dB max. permitted FO cable attenuation with 3 dB link power
margin
Table 8-107 Permitted cable lengths (fiber-optic cable - gigabit Ethernet)
Media module Fiber-optic cable type Max. permitted
cable length
Attenuation
MM992-2 (SC)
MM992-2 (C)
(SC)
62.5/125 µm
multimode fiber
350 m ≤3.1 dB/km at 850 nm; 1200 MHz×km; maximum insertion loss
0.5 dB; 4.5 dB max. permitted FO cable attenuation at 3 dB link
power margin
50/125 µm
multimode fiber
750 m ≤2.5 dB/km at 850 nm; 1200 MHz×km; maximum insertion loss
0.5 dB; 4.5 dB max. permitted FO cable attenuation at 3 dB link
power margin
MM992-2LD
(SC)
9/125 µm
single mode fiber
10 km ≤0.5 dB/km at 1310 nm; maximum insertion loss 0.5 dB; 6 dB
max. permitted FO cable attenuation at 3 dB link power margin
MM992-2LH
(SC)
9/125 µm
single mode fiber
40 km ≤0.4 dB/km at 1550 nm; maximum insertion loss 0.5 dB; 18 dB
max. permitted FO cable attenuation at 2 dB link power mar‐
gin, minimum cable attenuation 3 dB
MM992-2LH+
(SC)
9/125 µm
single mode fiber
70 km ≤0.28 dB/km at 1550 nm; maximum insertion loss 0.5 dB;
21 dB max. permitted FO cable attenuation at 2 dB link power
margin, minimum cable attenuation 8 dB
MM992-2ELH
(SC)
9/125 µm
single mode fiber
120 km ≤0.225 dB/km at 1550 nm; maximum insertion loss 0.5 dB;
27 dB max. permitted FO cable attenuation at 2 dB link power
margin, minimum cable attenuation 8 dB
Copper / fiber-optic cables
Table 8-108 Permitted cable lengths (copper cable/fiber-optic cable) for the SFP media module
Media module Max. permitted cable length
MM992-2SFP
*)
Depending on the SFP transceiver used.
*)
You will find further information in the compact operating instructions "Transceiver SFP/SFP+".
Attenuators
Transceivers of the types LH, LH+, ELH and ELH200 are designed for long distances and
therefore send more power than they can receive.
If you establish a connection between such transceivers with a short cable length, use
attenuators. Attenuators increase the attenuation and therefore protect the receiving diode.
Select the attenuation so that the transmit power (transmitter output) behind the attenuator is
lower than the maximum received power (input power):
Transmitter output max. [dBm] - attenuator [dB] < input power max. [dBm]
Technical specifications
8.9 MM900 technical specifications
SCALANCE X-300
Operating Instructions, 11/2019, A5E01113043-24 209