Operation; Introduction; Automatic Evaluation; Framing Evaluation - Fluke 635 User Manual

Chapter 3

Operation

3-1. Introduction

This chapter of the manual includes operation procedures for the most
commonly used tests of the QuickBERT-T1 and QuickCHECK-T1 test sets.

3-2. Automatic Evaluation

When the RESTART key is pressed, the unit automatically evaluates the
incoming signal for framing type, line coding, and BERT patterns. The test set
first determines the frame type that is currently being used on the line (D4,
ESF, SLC96, or NONE). Once the frame type has been detected, it determines
the pattern that is being transmitted on the line (see section 2-43 for a list of
supported BERT patterns). If the test set is unable to detect one of these BERT
patterns, then none of the green Pattern LEDs will illuminate, indicating either
live traffic or the presence of a pattern not supported by the unit.
The evaluation cycle will only operate if there is a valid input signal present at
the RX jack. If the input signal disappears during the cycle, the unit will stop
evaluating and wait for the signal to reappear.
The receiver and transmitter of the QuickBERT-T1 are totally independent of
each other (except when the Thru Tx pattern is selected). The evaluated Rx
signal and the receiver setup have no effect on the transmitter. The transmit
signal will always be transmitted according to the manual setup.
3-3.

Framing Evaluation

The QuickBERT-T1 and QuickCHECK-T1 evaluate the incoming signal to
determine the framing type: D4, ESF, or SLC96. If one of these framing types
is detected, the corresponding Framing LED illuminates. If the unit does not
recognize the framing type, the NONE LED will illuminate while the unit
attempts to establish frame sync.
3-1