Operating instructions

R&S ESCI [SENSe:]ADEMod - Subsystem
1166.6004.12 6.127 E-1
SENSe Subsystem
The SENSe subsystem is organized in several subsystems. The commands of these subsystems
directly control device-specific settings, they do not refer to the signal characteristics of the
measurement signal.
The SENSe subsystem controls the essential parameters of the receiver. In accordance with the SCPI
standard, the keyword "SENSe" is optional for this reason, which means that it is not necessary to
include the SENSe node in command sequences.
The measurement windows are selected by SENSe1 and SENSe2:
SENSe1 = Modification of screen A settings
SENSe2 = Modification of screen B settings.
Screen A is automatically selected if 1 or 2 is missing.
In the receiver mode, the screen partitioning for the split-screen mode is fixed – bargraph at top and
scan display below. Therefore, the numeric suffix is not required to select the measurement window.
[SENSe:]ADEMod - Subsystem
The purpose of the commands defined below is to set up the instrument for the measurement of FM,
PM and AM modulated signals in a way that allows to obtain as many measurement results as possible
with a single shot measurement.
For that purpose the instrument has been equipped with a demodulator that is capable of performing
both FM, PM and AM demodulation at a time. Additionally maximum, minimum and average or current
values can be obtained in parallel over a selected number of measurements. In order to make it suitable
for burst signals the demodulator can be configured in terms of pretrigger time, sample rate and record
length.
Note: Demodulation will be performed offline, that means, on signals previously stored into memory.
The I/Q memory available for that purpose is 2 x 128 k samples. The sample rate can be
selected in the range of 15.625 kHz to 32 MHz.
Example:
For a Bluetooth signal, the signal schematic under request is described in the following diagram:
Frequency versus time:
t
Record Length
Trigger
Signal
Offset
Samples
Measurement results of interest are:
! FM Offset
! FM Deviation (maximum and minimum) for signal modulated with '1'-values only