Endace DAG 5.2X, User Manual

Page: 54 / 66

EDM01-33v1 DAG_7.5G4_Card_User_Guide
50 ©2008 Endace Technology Ltd. Confidential - Version 1 - November 2008
Two Cards No Reference
Overview
If you are using two DAG cards in a single host computer with no reference clock, you must
synchronize the DAG cards using the same method if you wish to compare the timestamps
between the two DAG cards. You may wish to do this for example if the two DAG cards
monitor different directions of a single full-duplex link. You can synchronize the DAG cards
in two ways:
•
One DAG card can be a clock master for the second. This is useful if you want both
DAG cards to be accurately synchronized with each other, but not so for absolute time
of packet time-stamps, or
• One DAG card can synchronize to the host and also act as a master for the second
DAG card.
Synchronizing with Each Other
Although the master DAG card’s clock drifts against UTC, the DAG cards will be locked
together. This is achieved by connecting the time synchronization connectors of both DAG
cards using a DUCK crossover cable 52 (page ) ( Note: A 4-pin to RJ45 Adapter may be
required).
Configure one of the DAG cards as the master so that the other defaults to being a slave as
follows:
dagclock –d0 none overout
Output:
muxin none
muxout over
status Not Synchronised Threshold 596ns Failures 0 Resyncs 0
error Freq 0ppb Phase 0ns Worst Freq 213ppb Worst Phase 251ns
crystal Actual 100000000Hz Synthesized 67108864Hz
input Total 0 Bad 0 Singles Missed 0 Longest Sequence Missed 0
start Thu Apr 28 14:48:34 2007
host Thu Apr 28 14:48:34 2007
dag No active input - Free running
Note: The slave DAG card configuration is not shown as the default configuration will
work.