GE UR series, Instruction Manual

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2-18 L60 Line Phase Comparison System GE Multilin
2.2 SPECIFICATIONS 2 PRODUCT DESCRIPTION
2
ETHERNET SWITCH FIBER OPTIC PORTS
Maximum fiber segment length calculation:
The maximum fiber segment length between two adjacent
switches or between a switch and a device is calculated as fol-
lows. First, calculate the optical power budget (OPB) of each
device using the manufacturer’s data sheets.
where OPB = optical power budget, P
T
= transmitter output power,
and P
R
= receiver sensitivity.
The worst case optical power budget (OPB
WORST
) is then calcu-
lated by taking the lower of the two calculated power budgets, sub-
tracting 1 dB for LED aging, and then subtracting the total insertion
loss. The total insertion loss is calculated by multiplying the num-
ber of connectors in each single fiber path by 0.5 dB. For example,
with a single fiber cable between the two devices, there will be a
minimum of two connections in either transmit or receive fiber
paths for a total insertion loss of 1db for either direction:
The worst-case optical power budget between two type 2T or 2S
modules using a single fiber cable is:
To calculate the maximum fiber length, divide the worst-case opti-
cal power budget by the cable attenuation per unit distance speci-
fied in the manufacturer data sheets. For example, typical
attenuation for 62.5/125
μ
m glass fiber optic cable is approxi-
mately 2.8 dB per km. In our example, this would result in the fol-
lowing maximum fiber length:
The customer must use the attenuation specified within the manu-
facturer data sheets for accurate calculation of the maximum fiber
length.
ETHERNET SWITCH 10/100BASE-T PORTS
Connector type: RJ45
MAXIMUM 10 MBPS ETHERNET SEGMENT LENGTHS
Unshielded twisted pair: 100 m (328 ft.)
Shielded twisted pair: 150 m (492 ft.)
MAXIMUM STANDARD FAST ETHERNET SEGMENT LENGTHS
10Base-T (CAT 3, 4, 5 UTP): 100 m (328 ft.)
100Base-TX (CAT 5 UTP):100 m (328 ft.)
Shielded twisted pair: 150 m (492 ft.)
2.2.9 INTER-RELAY COMMUNICATIONS
SHIELDED TWISTED-PAIR INTERFACE OPTIONS
RS422 distance is based on transmitter power
and does not take into consideration the clock
source provided by the user.
LINK POWER BUDGET
These power budgets are calculated from the
manufacturer’s worst-case transmitter power
and worst case receiver sensitivity.
OPB P
T MIN
( )
P
R MIN
( )
– =
Total insertion loss number of connectors 0.5 dB
×
=
2 0.5 dB
×
= 1.0 dB =
OPB
WORST
OPB 1 dB (LED aging)
–
total insertion loss
– =
10 dB 1 dB
–
1 dB
–
8 dB
=
Maximum fiber length
OPB
WORST
(in dB)
cable loss (in dB/km)
------------------------------------------------------- =
8 dB
2.8 dB/km
--------------------------- =
2.8 km
=
INTERFACE TYPE TYPICAL DISTANCE
RS422 1200 m
G.703 100 m
NOTE
EMITTER,
FIBER TYPE TRANSMIT
POWER
RECEIVED
SENSITIVITY
POWER
BUDGET
820 nm LED,
Multimode –20 dBm –30 dBm 10 dB
1300 nm LED,
Multimode –21 dBm –30 dBm 9 dB
1300 nm ELED,
Singlemode –23 dBm –32 dBm 9 dB
1300 nm Laser,
Singlemode –1 dBm –30 dBm 29 dB
1550 nm Laser,
Singlemode +5 dBm –30 dBm 35 dB
NOTE