Common Measurement Settings
R&S
®
FSW
438
User Manual 1173.9411.02 ─ 43
Remote command:
Noise Source Control
The R&S
FSW provides a connector ("NOISE SOURCE CONTROL") with a 28
V volt-
age supply for an external noise source. By switching the supply voltage for an exter-
nal noise source on or off in the firmware, you can enable or disable the device as
required.
External noise sources are useful when you are measuring power levels that fall below
the noise floor of the R&S
FSW itself, for example when measuring the noise level of
an amplifier.
In this case, you can first connect an external noise source (whose noise power level is
known in advance) to the R&S
FSW and measure the total noise power. From this
value you can determine the noise power of the R&S
FSW. Then when you measure
the power level of the actual DUT, you can deduct the known noise level from the total
power to obtain the power level of the DUT.
Remote command:
8.2.7
Trigger Input/Output Settings
Access
: "Overview" > "Trigger" > "Trigger In/Out"
Or:
[TRIG] > "Trigger Config" > "Trigger In/Out"
The R&S
FSW can use a signal from an external device as a trigger to capture data.
Alternatively, the internal trigger signal used by the R&S
FSW can be output for use by
other connected devices.
Providing trigger signals as output is described in detail in
and Providing Trigger Signals"
on page 363 and
Chapter 8.2.8, "How to Output a Trig-
Trigger 2/3
Data Input and Output
