EDM01-36v10 DAG_9.2X2_Card_User_Guide - Installation
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©2010 - 2012 Endace Technology Ltd. Confidential - Version 10 - May 2012
Power input
Note:
The optical power input to the DAG card must be within the receiver’s dynamic range. See the previous
table for details. If it is slightly outside of this range it will cause an increased bit error rate. If it is
significantly outside of this range the system will not be able to lock onto the signal.
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. In
extreme cases, excess power can damage the receiver.
When you set up the DAG card you should measure the optical power at the receiver and ensure that it is
within the specified power range. If it is not, adjust the input power as follows:
•
Insert an optical attenuator if power is too high, or
•
Change the splitter ratio if power is too high or too low.
Splitter losses
Splitters have the insertion losses either marked on their packaging or described in their accompanying
documentation. General guidelines are as follows:
•
A 50:50 splitter will have an insertion loss of between 3 dB and 4 dB on each output.
•
90:10 splitter will have losses of about 10 dB in the high loss output, and <2 dB in the low loss
output.
Note:
Endace recommends that you do not use a combination of single-mode and multi-mode fibers and optics
modules on the same link, as the quality of the received signal cannot be guaranteed.
If you have no choice but to mix single-mode and multi-mode, please be aware that a single mode input
connected to a multi-mode fiber will have some attenuation but may still be acceptable. However a multi-
mode input connected to a single-mode fiber will likely have large and unpredictable losses.
Pluggable copper transceivers
The DAG card supports industry standard Small Form-factor pluggable (SFP) copper transceivers.
The transceivers consist of two parts:
•
Mechanical chassis attached to the circuit board
•
Transceiver unit which may be inserted into the chassis
Endace recommends that you use Cat6 copper cable. The DAG card copper module specification is shown
below:
Part
Type
Data Rate
TXR-1000TX
1000 Base-T
less than 1.25 Gbps (RJ-45 IEEE 802.3)
Note:
If a copper transceiver is unplugged and then plugged in again you must run
dagconfig default
to
initialize the transceiver for the link configuration. It also checks the compatibility of all the modules with
the DAG card, and will not power on mismatched modules.
