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    Line coding and bit-clock regeneration

    There are different kind of line codes, such as, Non-return to zero level (NRZ-L), Return to zero - alternate mark inversion (RZ-AMI), Bi-phase - level (BiΦ-L), Non-return to zero-mark (NRZ-M). read more...       

        To perform the Experiment please follow the procedure:

1.  Install the run time engine program to operate each VI.

2.  Activate the DSA by pressing the  from the tool bar, and then press the in each.


3. Select the NRZ-L line code by returning the Sequence Generator module's DIP- switches to 00.

4.  Launch and run the NI ELVIS II Dynamic signal Analzyer VI.


5. Adjust the signal analyzer's controls as follows:


Input Settings

Source Channel to Channel 1

FFT Settings

Frequency span to 40,000

Resolution to 400

Windows to 7 term B-Harris

Trigger Settings


Frequency Display

Units to dB

Mode to RMS

Scale to Auto

Voltage Range to ±10 V


Mode to RMS

Weighting to exponential

# of averages to 3


6. Set the Sequence Generator module to output the NRZ-L line code.


7. Count the number of lobes in the signal's spectrum (for a span of 40kHz). Record this number in table 2 below.

8. Repeat step 7 for the other three codes:


Line code

Lobes ( in 40KHz span)











9.  Set the Sequence Generator module to output the NRZ-L line code.


10. Activate the signal analyzer's cursors (by checking Cursors On box).


11. Align one the cursors with the first null (the one between the first and second lobes in the signal's spectrum).


12. Measure the null's frequency and record this in table below


Line code

Frequency of first null









13. Measure and record the frequency of the first null in the spectrum of the other three line codes.


14. Based on your result in tables 2 and 3, which of the four codes in the odd one out?