Tektronix 80C12B Series, Руководство пользователя, Страница: 24 / 44

Operating Basics
3. Firmly tighten the cable connector or the adapter shell. Tighten with fi nger
pressure only.
4. To remove, loosen the cable connector or adapter shell and pull out without
rotating or bending the cable or adapter.
Attenuating Optical
Signals
To keep the optical input power to an appropriate level, you may need to attenuate
the optical signal. The 80C12B absolute maximum optical signal levels are:
4 mW average optical power at 850 nm
2 mW average optical power at 1310 nm and 1550 nm
10 mW peak at wavelength of highest responsivity
CAUTION.
To avoid damaging the optical input of the module, attenuate the input
optical signal to the absolute maximum optical signal levels listed above.
NOTE.
The 80C12B module can have a somewhat deteriorated response for
signals greater than 800 μ W
p-p
(1310 nm and 1550 nm) and 1300 μ W
p-p
(850 nm).
Optical sampling modules can have dynamic ranges exceeded without obvious
visual indication on the waveform because the overloaded signal output of the
photodetector may still be within the dynamic range of the internal electrical
sampler. To ensure accurate measurements, make sure that input signal levels are
within allowed ranges.
System Interaction
Your optical module is a part of a larger instrument system. Most optical module
functions are controlled automatically by the main instrument. These include such
things as vertical scaling and horizontal sampling rate. You do not directly control
these parameters; they are controlled for you as you perform tasks on the main
instrument. The parameters that you control from the optical module front panel
are explained in the
Front Panel Controls section.
An additional optical module function that you control from the main instrument
is external channel attenuation. External Attenuation lets you enter a number
representing any external attenuation you have added to a channel.
10 80C12B Optical Sampling Module User Manual