Endace Measurement Systems.
http://www.endace.com
EDM01.05-10r1 DAG 4.3S Card User Manual
34
Revision 6. 22 September 2005.
6.2.2 Two Cards no Reference Time Synchronization
, continued
Locking cards
together
Although the master card’s clock will drift against UTC, the cards are
locked together.
The cards are locked together by connecting the synchronization
connector ports of both cards with a standard RJ-45 Ethernet cross-over
cable.
Configure one of the cards as the master, the other defaults to being a
slave:
dagclock –d dag0 none overout
Preventing
time-stamp
drift
To prevent DAG card time-stamps drifting against UTC, one card is
synchronized to the host PC clock, which in turn utilises NTP. This
provides a master signal to the second card.
In this case, connect synchronization connectors with a standard RJ-45
Ethernet cross-over cable.
Configure one card to synchronize to the PC clock, and output a RS-422
synchronization signal to the second card.
dag@endace:~$ dagclock –d dag0 none overin overout
muxin overin
muxout overout
6.2.3 Card with Reference Time Synchronization
Description
The best timestamp accuracy occurs when DAG card is connected to an
external clock reference, such as a GPS or CDMA time receiver.
Pulse signal
from external
sources
The DAG synchronization connector accepts a RS-422 Pulse Per Second
[PPS] signal from external sources.
This is derived directly from a reference source, or distributed through the
Endace TDS [Time Distribution Server] modules which allow multiple
DAG cards to use a single receiver.
Continued on next page
