Endace DAG 4.3GE, Руководство пользователя

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Endace Measurement Systems Ltd EDM01.05-01r1 DAG 4.3GE Card User Manual
www.endace.com
3.0 SETTING OPTICAL POWER
Description The optical power range depends on the particular device fitted on the
DAG 4.3GE card.
The DAG 4.3GE card is shipped fitted with two 1000baseSX FTRJ 8519F
850nm multi-mode short range optics modules by default.
Optical power
measure Optical power is measured in dBm – decibels relative to 1 mW where 10
dB is equivalent to a factor of 10 in power.
The numbers are all negative, showing powers below 1 mW. The most
sensitive devices can work down to about –30 dBm, or 1 uW.
Configuration Table 3-1 shows the DAG 4.3GE card optics power module configuration.
Part # Fibre Data Rate Max Power
[dBm]
Min Power
[dBm]
Nominal Pwr
[dBm]
FTR8519F MMF 1000 0 -22 -14
In this chapter This chapter covers the following sections of information.
•
Optical Power Input
•
Splitter Losses
3.1 Optical Power Input
Description The optical power input to DAG must be within the receiver’s dynamic
range of 0 to -22dBm.
When optical power is slightly out of range an increased bit error rate is
experienced. If power is well out of range the system cannot lock onto the
Ethernet signal. In extreme cases of being out range excess power will
damage a receiver.
When power is above the upper limit the optical receiver saturates and
fails to function. When power is below the lower limit the bit error rate
increases until the device is unable to obtain lock and fails.
Input power When the DAG card is set up, measure the optical power at the receiver
and ensure that it is well within the specified power range.
Input power is adjusted by:
•
Changing splitter ratio if power is too high or too low, or
•
Inserting an optical attenuator if power is too high.
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Revision 6. 22 September 2005.