Rohde & Schwarz ZNL Series, User Manual

Page: 33 / 240

Configuration
R&S
®
ZNL
33 User Manual 1178.5989.02 ─ 06
RF Input Protection
The RF input connector of the R&S ZNL must be protected against signal levels that
exceed the ranges specified in the data sheet. Therefore, the R&S ZNL is equipped
with an overload protection mechanism. This mechanism becomes active as soon as
the power at the input mixer exceeds the specified limit. It ensures that the connection
between RF input and input mixer is cut off.
When the overload protection is activated, an error message is displayed in the status
bar ( "INPUT OVLD" ), and a message box informs you that the RF Input was discon-
nected. Furthermore, a status bit (bit 3) in the
STAT:QUES:POW
status register is set.
In this case you must decrease the level at the RF input connector and then close the
message box. Then measurement is possible again. Reactivating the RF input is also
possible via the remote command
INPut<ip>:ATTenuation:PROTection:RESet
.
The power sensor functions are described in the R&S ZNL User Manual.
Radio Frequency State ................................................................................................ 33
Impedance ................................................................................................................... 33
Radio Frequency State
Activates input from the "RF Input" connector.
Remote command:
INPut<ip>:SELect
on page 110
Impedance
For some measurements, the reference impedance for the measured levels of the
R&S
ZNL can be set to 50
Ω
or 75
Ω
.
Select 75
Ω
if the 50
Ω
input impedance is transformed to a higher impedance using a
75
Ω
adapter of the RAZ type. (That corresponds to 25
Ω
in series to the input impe-
dance of the instrument.) The correction value in this case is 1.76 dB = 10 log (75
Ω
/
50
Ω
).
This value also affects the unit conversion (see " Reference Level " on page 42).
Remote command:
INPut<ip>:IMPedance
on page 110
5.3.2 Settings for Input from I/Q Data Files
Access : "Overview" > "Input/Frontend" > "Input Source" > "I/Q File"
Or: [INPUT/OUTPUT] > "InputSourceConfig" > "Input Source" > "I/Q File"
Receiving Data Input and Providing Data Output