EDM01-09v7 DAG 3.8S Card User Guide
©2005
11
Version 9: May 2006
Chapter 3: Setting Optical Power
Description
The optical power range depends on the particular transceiver module
fitted to the DAG 3.8S card.
The power range depends on the particular device installed on the DAG
card. The DAG 3.8S card is shipped fitted with HFBR 5208EM module
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 µW.
Configuration
The following table describes the DAG 3.8S card optics power module
configuration. MMF = Multi Mode Fibre. SMF = Single Mode Fibre.
Part #
Fibre
Data Rate Max Power
[dBm]
Min Power
[dBm]
Nominal Pwr
[dBm]
HFBR 5208EM
MMF
155/622
-14
-26
-20
HFCT 5208EM
SMF
155/622
-7
-28
-20
In this chapter
This chapter covers the following sections of information.
•
DAG 3.8S Card Optical Power Input
•
Splitter Losses
3.1 DAG 3.8S Card Optical Power Input
Description
The optical power input into the DAG 3.8S card must be within the
receiver’s dynamic range.
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
SONET frames. 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
The DAG 3.8S card is set up to measure the optical power at the receiver,
and to make sure 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.
Summary of Contents for DAG 3.8S
Page 1: ......
Page 5: ...EDM01 09v7 DAG 3 8S Card User Guide 2005 ii Version 9 May 2006...
Page 11: ...EDM01 09v7 DAG 3 8S Card User Guide 2005 6 Version 9 May 2006...
Page 15: ...EDM01 09v7 DAG 3 8S Card User Guide 2005 10 Version 9 May 2006...
Page 31: ...EDM01 09v7 DAG 3 8S Card User Guide 2005 26 Version 9 May 2006...
Page 45: ...EDM01 09v7 DAG 3 8S Card User Guide 2005 40 Version 9 May 2006...