12
6651-2231
RS-232
Electrical specification
EIA RS-232
Data rate
300 bit/s – 250 kbit/s
Protocol
Asynchronous or synchronous
Data format
9 – 12 bits in asynchronous mode
Any type in synchronous mode
Data retiming
Asynchronous mode only
Transmission range
15 m
Isolation to
Status and Power port
Connection
9-pin D-sub female (DCE)
Shielded cable
Not required, except when installed in railway applications as
signalling and telecommunications apparatus and located close
to rails*
Conductive housing
Isolated to all other circuits and housings
* To minimise the risk of interference, a shielded cable is recommended when the cable is located inside 3 m
boundary to the rails and connected to this port.
The cable shield should be properly connected (360°) to an earthing point within 1 m from this port.
This earthing point should have a low impedance connection to the conductive enclosure of the apparatus
cabinet, or similar, where the unit is built-in. This conductive enclosure should be connected to the earthing
system of an installation and may be directly connected to the protective earth.
Optical Power Budget
The allowed link length is calculated from the optical power budget (OPB), the available optical
power for a fibre-optic link, and the attenuation of the fibre, comprising losses due to in-line
connectors, splices, optical switches and a margin for link ageing (typical 1.5 dB for 1300 nm).
The worst-case optical power budget (OPB) in dB for a fibre-optic link is determined by the differ-
ence between the transmitter’s output optical power (min) and the receiver input sensitivity (max).
FX (Fibre)
SM-LC80
SM-LC40
SM-LC20
MM-LC2
Fibre connector
LC duplex
LC duplex
LC duplex
LC duplex
Fibre type
Singlemode
9/125
m
m
Singlemode
9/125
m
m
Singlemode
9/125
m
m
Multimode,
62.5/125
m
m
Wavelength
1550 nm
1310 nm
1310 nm
1310 nm
Transmitter
Output optical power min/max
–5/0 dBm
–5/0 dBm
–15/–8 dBm
–20/–14
dBm
Receiver
Input sensitivity, max
–35 dBm
–35 dBm
–34 dBm
–31 dBm
Receiver
Input optical power, max
0 dBm
0 dBm
0 dBm
–8 dBm
Optical power budget,
worst-case
30 dB
30 dB
19 dB
11 dB
Transceiver type
Small Form Factor Pluggable (SFP)
Multi-Sourcing Agreement (MSA) compliant
Laser class
Class 1, IEC 825-1 Accessible Emission Limit (AEL)
