
64
Setting the Interfaces - SONET Operation
Setting THRU Mode
Setting THRU Mode
Description
THRU mode is used to non-intrusively monitor SONET lines where no protected
monitor points are available. To enable THRU mode select the
page. Select SIGNAL RATE before selecting THRU mode.
The entire frame can be errorred at a user defined rate if PAYLOAD OVERWRITE
and TOH+POH CHANNEL OVERWRITE are both set to
. If either
overwrite is enabled the ENTIRE FRAME ERROR RATE function is disabled.
There are nominally three modes of operation as follows:
1. Transparent mode: This is the case when the PAYLOAD OVERWRITE field is
set to OFF. The received signal is passed through the transmitter completely
unchanged. The figure below illustrates the settings for this mode.
2. Hitless THRU Mode: This mode enables you to change the channel under test
and the payload mapping without causing errors in the line signal or any other
payload channel, or having to switch out of THRU mode. When you select a
Payload Overwrite choice (other than OFF) an additional field is displayed which
allows you to enable/disable Payload Overwrite. If Payload Overwrite is disabled
the instrument remains transmitting while you select another channel/tributary (see
figure on next page). In this mode any Section or Line CV errors are recalculated
before transmission.
TRANSMIT
MAIN SETTINGS
OFF
SONET_Usr.bk Page 64 Wednesday, December 13, 2000 11:11 AM
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com