Waveform setup
R&S
®
RTB2000
60
User Manual 1333.1611.02 ─ 11
Vert. Position Knob
Selects the parameter to be changed with the [Offset/Position (upper knob)]: "Offset" or
"Position". By default, position is set. [Preset] does not affect the assignment.
Channel <n>
Opens the channel menu.
State
Switches the selected channel on or off.
Remote command:
Coupling
Selects the input coupling, which influences the signal path between input connector
and the following internal signal stage. The current coupling of each channel is shown
in the waveform labels below the grid.
"AC"
AC coupling is useful if the DC component of a signal is of no inter-
est. AC coupling blocks the DC component of the signal so that the
waveform is centered on zero volts.
If AC coupling is set, the attenuation of passive probes has no effect,
and voltage is applied to the instrument with factor 1:1. Observe the
voltage limits, otherwise you can damage the instrument.
"DC"
With DC coupling, the input signal passes unchanged, all signal com-
ponents are shown.
Remote command:
Bandwidth
Selects the bandwidth limit. At full bandwidth, all frequencies in the specified range of
the instrument are acquired and displayed accurately with less than 3
dB attenuation.
Full bandwidth is used for most applications.
To reduce noise, you can set a frequency limit. Higher frequencies are removed from
the signal. Limited bandwidth is indicated by "B
W
" in the waveform label.
For analog applications, the highest signal frequency determines the required oscillo-
scope bandwidth. The oscilloscope bandwidth should be at least 3 times higher than
the maximum frequency included in the analog test signal to measure the amplitude
without aliasing.
Most test signals are more complex than a simple sine wave and include several spec-
tral components. A digital signal, for example, is built up of several odd harmonics. For
digital signals, the oscilloscope bandwidth should be at least 5 times higher than the
clock frequency to be measured.
The oscilloscope is not an autonomous system. You need a probe to measure the sig-
nal, and the probe has a limited bandwidth, too. The combination of oscilloscope and
probe creates a system bandwidth. To reduce the effect of the probe on the system
bandwidth, the probe bandwidth should exceed the bandwidth of the oscilloscope, the
recommended factor is 1.5 x oscilloscope bandwidth.
Vertical setup
