Triggering the Oscilloscope

External Trigger Input

2 Press the External softkey to display the external trigger probe menu.

Attenuation

Measurement

Input impedance

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factor

units

(54640-series)

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Probe Attenuation Turn the Entry knob to set the attenuation factor displayed in the Probe softkey for the connected probe. The attenuation factor can be set from 0.1:1 to 1000:1 in a 1-2-5 sequence.

For 2-channel oscilloscopes that have the Ext Trigger connector on the front panel, when you connect an AutoProbe self-sensing probe, the oscilloscope will automatically configure your probe to the correct attenuation factor.

The probe correction factor must be set properly for measurements to be made correctly.

Probe Units Press the Units softkey to select the proper measurement unit for the connected probe. Select Volts for a voltage probe and select Amps for a current probe. Measurement results, channel sensitivity, and trigger level will reflect the measurement units you have selected.

Input Impedance The 54620-series oscilloscope external trigger input impedance is always 1 M. The 54640-series oscilloscope external trigger input impedance can be set to either 1M Ohm or 50 Ohm by pressing the Imped softkey.

50 Ohm mode matches 50-ohm cables commonly used in making high frequency measurements. This impedance matching gives you the most accurate measurements since reflections are minimized along the signal path.

1M Ohm mode is for use with probes and for general-purpose measurements. The higher impedance minimizes the loading effect of the oscilloscope on the circuit under test.

For 2-channel oscilloscopes that have the Ext Trigger connector on the front panel, when you connect an AutoProbe self-sensing probe, the oscilloscope will automatically configure your probe to the correct impedance.

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Agilent Technologies 54621D, 24A, 42A, 54621A, 22A, 41A manual Previous menu