Tx Pattern Key (Quickbert-T1 Only); Qrss - Fluke 635 User Manual

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Users Manual
DSX MON - The DSX Monitor Mode is typically used to monitor in-service
T1 spans through a DSX monitor jack that is resistor-isolated from the span.
When DSX MON is selected, the receiver is terminated into 100 ohms. Due to
the loading effect of the 100-ohm termination in series with the isolation
resistors, there is approximately a 20 dB line drop seen by the receiver. See
Chapter 3.
TERM - The Terminate Mode is used when the span is being terminated by the
QuickBERT-T1 or QuickCHECK-T1. It is typically used for an out-of-service
BERT (see section 3-8).
BRDG - The Bridge Mode is typically used to monitor in-service T-spans that
do not have a DSX monitor jack. The test set assumes a bridged connection
consists of a direct connection to one side of the span, and that the connection
is not resistor-isolated to the receive connector of the test set. The receiver is
set to the high-impedance state of greater than 1000 ohms.

2-43. TX PATTERN Key (QuickBERT-T1 only)

The TX PATTERN key controls the data content of the signal being
transmitted by the QuickBERT-T1. Twelve patterns are available for selection.
The yellow Pattern LEDs illuminate to indicate that the corresponding pattern
is being transmitted. To change the pattern, simply press the TX PATTERN
key.
Since the transmitter and receiver of the QuickBERT-T1 are totally
independent, the pattern being transmitted is not necessarily the pattern being
received. So while the yellow Pattern LEDs indicate the pattern being
transmitted, the green Pattern LEDs indicate the pattern being received. No
selection is necessary for the received pattern.
The QuickBERT-T1 automatically evaluates the signal present at the receiver
and the appropriate LED illuminates indicating pattern synchronization has
been achieved. Sections 2-44 through 2-55 provide detailed descriptions of the
individual patterns.

2-44. QRSS

20
The quasi-random signal source (QRSS) pattern is modified 2 -1
pseudorandom pattern which allows a maximum of 14 sequential zeros and 20
sequential ones. The QRSS pattern is the most widely used pattern to test DS1
facilities. It provides a random set of stresses including long strings of zeros
and ones. Unless B8ZS is invoked, QRSS violates the ones-density
requirements when framed.
2-18