T1 Tester Mode Menus (Option 50)
In T1 Tester mode (Option 50, S331D only), the
FREQ/DIST
and
AMPLITUDE
hard keys
are not used. Pressing the
MEAS/DISP
key in T1 Tester mode causes the soft keys, below,
to be displayed:
q
BERT
— Activates menus that are used Bit Error Rate Testing (BERT).
q
Setup BERT
— Activates menus that are used to set BERT testing op-
tions.
q
Framing Mode
— Selects the framing mode to be used.
q
Auto
— Automatically detects the received framing mode.
q
D4 SF
— Sets the T1 framing mode to Super Frame.
q
ESF
— Sets the T1 framing mode to Extended Super Frame.
q
Back
— Returns to the previous menu.
q
Receive Input
q
Terminate
— Terminates the circuit under test with 100
W
. Termi-
nate mode is used to test out of service or newly installed T1 lines
when there is no traffic data.
q
Bridged
— Bridged mode provides greater than 1 k
W
impedance to
test the in-service line by bridging the receiver input across T1
lines.
q
M20 dB
— Monitor mode adds 20 dB of gain, and is used
when the connection to the circuit under test is through a 20 dB
pad. In the monitor mode the Cell Master sensitivity is increased
by 20 dB to account for the resistive loss at the port, and is set for
100
W
nominal input impedance. In this mode the technician
should be careful not to disturb the signal by using the wrong con-
nector.
q
Back
— Returns to the previous menu.
q
Pattern
— Opens a list of available BERT patterns. Use the soft keys
or the Up/Down arrow key to highlight a pattern and press
ENTER
to
select.
q
Line Coding
— Selects the line coding to be used.
q
B8ZS
— Bipolar with eight-zero substitution. A T1 code in which
bipolar violations are deliberately inserted if the user data contains
a string of eight or more consecutive zeros. B8ZS is used to en-
sure a sufficient number of transitions to maintain system synchro-
nization.
q
AMI
— Alternate Mark Inversion. A bipolar signal in which ones
are encoded as pulses with alternating polarity, and zeros are en-
coded as zero amplitude.
q
Back — Returns to the previous menu.
q
More
q
Clock Source
— Selects the clock source.
q
Internal
— Uses the internal clock.
q
External
— The Cell Master clock is synchronized with the re-
ceived signal clock.
q
Back — Returns to the previous menu.
Chapter 2 Functions and Operations
2-33
