Fiber optic bi-directional communication
An interesting feature of optical fibers is that light traveling in one direction is largely unaffected by light traveling in the opposite direction along the same fiber. This makes sense when you think about it. If you were to shine two torches at each other, their beams wouldn't interfere with one another. read more...
To perform the Experiment please follow the procedure:
1. Install the run time engine program to operate each VI.
2. Activate
the
scope,
and
by pressing
the
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from
the tool bar, and then press the
in
each.
3. Set the mode control of the other red transmitter module to Digital.
4. Set the gain range control of the other receiver module to LO.
5. Turn the same receiver module's variable gain control to about the middle of its travel.
6. Adjust the scope as follows and take a screen shoot for Ch1
|
Channel 0 |
Channel 1 |
|
|
Volts/Div |
1 V |
1 V |
|
DC offset |
0 V |
-5 V " Trigger " |
|
Time/Div |
50 µ sec | 50 µ sec |
7. Make the following changes to the scope's set up." input coupling controls for both channel back to the AC position and take a screen shoot for Ch 1.
|
Channel 0 |
Channel 1 |
|
|
Volts/Div |
1 V |
0 V |
|
DC offset |
0 V |
" Edge " |
|
Time/Div |
100 µ sec | 100 µ sec |
9. It's clear that some of the digital message is super-imposed on the recovered on the recoved version of the analaog message? What's the name for this problem?
10. Which one of the coupler modules is causing this problem and why?
11. How can the analog message be cleaned ?
12. Why didn't the recovered version of the digital message ?