EXFO PSO-200 Optical Modulation Analyzer - Manual (Page 103)

Bit Pattern Analysis and the Gearbox
Optical Modulation Analyzer 95
Performing Detailed Bit Pattern Analysis with the Gearbox
From the previous example, the following bit stream is sent to the
transmitter: 1101 1000 1010 0101 0110 1001 1111 1110.
At the transmitter input, the stream looks like this:
The application needs to know which bit goes to which modulator input.
This is called alignment. The configuration file considers bit naming as
follows (by convention, the least significant bit is named “bit 0”):
For example, to indicate to the Gearbox that the bits are aligned this way:
The configuration file should define the inputs as follows (bit name values
are in the first column):
X0= 3
X1= 2
Y0= 1
Y1= 0