Specifications

4-21
Operating Features and Specifications
Error Location (Agilent 71612 or Agilent 70843 Option UHJ)
To initiate a measurement select then . The
instrument searches for the first bit errored bit in the pattern. The address of the errored bit
will be displayed along with the bit pattern surrounding the highlighted errored bit (see
below). The instrument performs Bit BER, Bit error count, and also Delta Bit BER, Delta
bit count on the captured bit.
Select then to view the BIT: results.
After an error is located the instrument displays:
BIT: Error Address nnn
Data window xxxx xxxx xxxx xxxx xxxx xxxx xxxy xxxx
• xxx.. - pattern around error, 28 bits before error and 3 bits after error are displayed
• y - the reference value of the errored bit in inverse video
Block BER
Block BER measures the BER of a range of bits in the pattern. It replaces normal BER
measurements. Ranges of bits must be a multiple of 32 bits with the block specified by a
start location and block length. This measurement is essential when trying to locate the
cause of systematic errors which can affect a section of bits, for example a corrupt header
in a SONET or SDH frame.
Pattern sync is affected since normal BER is replaced by the block results.
In general bit or block BER is not measured on every repetition of the pattern. The number
of repetitions depends on the pattern length.
Table 4-2 Pattern Length/Number of Repetitions for Bit/Block BER
Pattern length Number of repetitions
Odd 256
Multiple of 2 128
Multiple of 4 64
Multiple of 8 32
Multiple of 16 16
Multiple of 32 8
Multiple of 64 4
Multiple of 128 2
Multiple of 256 1
error location
CAPTURE ERROR
result pages
OTHER RESULTS