Keysight Technologies N774 C Series, Руководство пользователя

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Keysight N774xC Series Multiport Power Meter User’s Guide 65
User Interface Reference
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specifications. These bandwidths are reduced in steps, when longer
averaging times are used to improve the noise performance while
maintaining signal fidelity.
How to Set Automatic Gain for Averaging Modulated Signals
A fast Auto Gain switching is used to achieve the high dynamic range in
the N7744C and N7745C. In some applications, like determining the
average power of signals modulated with periods shorter than the
averaging time, this switching produces irregular readings. In such cases,
the Auto Gain should be turned off, as described in the N774xC
Programming Guide . This setting takes effect after setting the averaging
time on the port directly or via function parameters.
How to Choose the MinMax Function
MinMax function measures the incoming power and returns the
minimum value measured and the maximum value measured of the
selected channel. Note that this measurement is independent from the
graphical plot.
The difference between these values, delta P, is returned
in place of P, the power value.
This mode is intended principally for polarization dependent
measurements, but can be used for other types of measurement.
Reset MinMax - Use this option to reset the minimum value measured,
and the maximum value measured.
How to Use External Triggers
The Optical Multiport Power Meter allows you trigger the instrument to
perform tasks and to output trigger signals to external measurement
instruments using the rear panel BNC connectors.
1 Go to
Settings -> Measurement Settings
2 Set the Trigger configuration
By default, the trigger level at the external trigger connector is active
high. This means when a trigger rises above the high TTL level (rising
edge), a trigger is accepted.
You can select three modes of triggering from the trigger configuration
menu:
• Disabled - to disable the trigger connectors.
• Default - to enable the trigger connectors.
• Pass Through - an input trigger will generate an output trigger. This
lets you trigger another instrument almost simultaneously.