User guide

12
6651-2221
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 mm
Singlemode
9/125 mm
Singlemode
9/125 mm
Multimode,
62.5/125 mm
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)