7-23
IM WT3001E-51EN
Harmonic Measurement in Normal Measurement Mode (Option)
1
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Index
Explanation
For functional details, see section 7.1.
Set the PLL (Phase Locked Loop) source that is used to determine the fundamental
period, which acts as the reference in the analysis of the harmonic orders.
• Displayed Position of the Selected PLL Source
The selected PLL source is displayed in the upper right corner of the screen when
HRM SET is pressed.
Below is a display example when the PLL source is set to the voltage of Element1.
PLL source
Voltage
Element
• Selecting the PLL Source
Select the PLL source from the choices below. The selectable items vary depending
on the installed elements.
U1, I1, U2, I2, U3, I3, U4, I4, Ext Clk,
*1
and Smp Clk
*2
*1 If you select “Ext Clk,” harmonic measurement is performed using the frequency of the
signal applied to the external clock input connector as the fundamental frequency.
*2 Selectable in wide bandwidth harmonic measurement mode on models with the advanced
computation (/G6) option. If you select “Smp Clk,” harmonic measurement is performed
using 1/3000
th
of the frequency of the signal applied to the external clock input connector as
the fundamental frequency.
• When the PLL Source Is Set to Ext Clk or Smp Clk
Apply a clock signal to the external clock input connector (EXT CLK) on the rear panel
according to the following specifications.
EXT. CLK
• Ext Clk Specifications
Item
Specifications
Connector type
BNC connector
Frequency range 10 Hz to 2600 Hz
Input level
TTL
Input waveform
50% duty ratio rectangular wave
• Smp Clk Specifications (Selectable in Wide Bandwidth Harmonic
Measurement Mode)
Item
Specifications
Connector type
BNC connector
Frequency range Frequency equal to 3000 times the fundamental frequency of 0.1 Hz to 66 Hz
Input level
TTL
Input waveform
50% duty ratio rectangular wave
CAUTION
Applying a voltage outside the range of 0 to 5 V to the external clock input
connector (EXT CLK) can damage the instrument.
7.5 Selecting the PLL Source
