JDS Uniphase CellAdvisor JD780A Series, User Manual

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JD780A Series Analyzers
Using T1 Analyzer
531
4.
Toggle the Line Code soft key between AMI and B8ZS and select the line code type to send an
T1 signal:
–
AMI: It stands for Alternate Mark Inversion. A line code uses one three level signal to
convey binary digits in which successive binary ones (
“marks” or pulses) are of alternating
polarity, either positive or negative, equal in amplitude. A binary zero
(“space”) is
transmitted as no pulse or zero amplitude.
–
B8ZS: It stands for Bipolar with 8-Zero Substitution. A coding scheme in which the
transmitter "substitutes" a fixed pattern of ones, zeros, and BPVs in place of 8 consecutive
zeros.
5.
Press the Pattern soft key, and then select the stress pattern option from the following choices:
–
1-8: An eight-bit pattern that contains a single one, being used to test clock recovery.
–
1-16: A sixteen-bit pattern that contains a single one, being used to test clock recovery.
–
All 1
’S:
A pattern that causes line drivers to consume the maximum power.
–
All 0
’S:
A pattern that is often selected to verify HDB3 provisioning. Circuit will drop if
optioned for AMI.
–
Alternate: A pattern that alternates between ones and zeroes.
–
3-24: A twenty-four bit-pattern containing 3 ones with the longest length of consecutive
zeroes constrained to fifteen. It has ones density of 12.5% and is used to check clock
recovery.
–
QRSS: A pseudorandom pattern that is a common test pattern and simulates live traffic on
a circuit.
–
2e23: A pseudorandom pattern based on a 23 bit shift register.
–
2e15: A pseudorandom pattern based on a 15 bit shift register.
–
2e23 INV: Bit inversed pseudorandom pattern based on a 23 bit shift register.
–
2e15 INV: Bit inversed pseudorandom pattern based on a 15 bit shift register.
6.
Toggle the TX Clock soft key between Internal and RX and select the timing source option to
measure frequency and timing:
–
Internal: Internal clock uses an internal oscillator in case of external reference is not
available and the instrument does not transmit signal to synchronized equipment. The
instrument provides the clock to the unit under test and most cases in Loopback test mode.
–
RX: Transmit clock uses the frequency recovered from the received signal (Network Loop),
if accurate frequency measurement is required.
7.
Press the TX LBO soft key, and then select the level for TX Line Build Out option from the
following choices:
–
0 dB: Is used in most cases including that the test set is connected to the DSX front panel,
to CSU, to NIU or Channel Bank or that the cabling is less than about 130 feet in-between
test set and DSX.
–
-7.5 dB: Is used in cases that attenuation is needed where the T1 line is series connected
to 7.5 dB attenuator.
–
-15 dB: Is used in cases that attenuation is needed where the T1 line is series connected to
15 dB attenuator.
To start or stop testing:
1.
Press the MEASURE hot key.
2.
Press the BERT soft key, and then select the testing option as needed: Start , Stop , or Clear .
To select the error injection type:
1.
Press the Error Injection soft key, and then select the error injection type: None , 1E-3 , 1E-4 ,
1E-5 , or Single .