5-6
IM 701830-01E
5.5
Selecting Input Coupling
(For High-Speed Isolation/High-Speed/High-Resolution, High-Voltage, Isolation/High-
Resolution, Isolation Modules)
≡
For a description of this function, refer to page 1-4.
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Function
Input coupling
The following three types of input coupling are available.
AC
: Acquires and displays only the AC content of the input signal.
DC
: Acquires and displays both the DC and the AC content of the input signal.
GND
: Checks the ground level.
Input coupling and frequency characteristic
The frequency characteristic when “
AC
” or “
DC
” is selected is shown below.
Note that low-frequency signals and low-frequency contents are not acquired if “
AC
” is
selected.
0 dB
-3 dB
-3 dB point*
Attenuation
0 dB
-3 dB
-3 dB point*
Attenuation
Lower frequency
-3 dB point when AC coupling*
Input frequency
When “AC” is selected
When “DC” is selected
Input frequency
* The value varies for each input module. For details, refer to Section 15.16 to 15.19.
CAUTION
• When the input coupling is set to “AC” and the frequency of the input signal is less
than 1 Hz, the input terminal of the instrument does not attenuate the signal to 1/10
even if a probe with attenuation ratio of 10:1 and input resistance of 10 M
Ω
is used.
Therefore, make sure not to input a voltage that has a signal component less than
1 Hz that exceeds the maximum input voltage of each module.
• Do not apply voltages exceeding the maximum input voltage or the maximum
allowable common mode voltage of each of the input modules. It may damage the
input section.
Operating Procedure
1.
Press one of the
CH1
to
CH16
keys to select the desired channel.
2.
Press the “
Coupling
” soft key to select “
DC
”, “
AC
” or “
GND
”.