The Spectrum Application (RF Measurements)
R&S
®
FPL1000
277
User Manual 1178.3370.02 ─ 11
RF Input Protection
The RF input connector of the R&S
FPL1000 must be protected against signal levels
that exceed the ranges specified in the data sheet. Therefore, the R&S
FPL1000 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.
The RF input connector of the R&S
FPL1000 must be protected against signal levels
that exceed the ranges specified in the data sheet. Therefore, the R&S
FPL1000 is
equipped with an overload protection mechanism for DC and signal frequencies up to
30
MHz. 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
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Radio Frequency State
Activates input from the "RF Input" connector.
Remote command:
Impedance
For some measurements, the reference impedance for the measured levels of the
R&S
FPL1000 can be set to 50
Ω
or 75
Ω
.
For GSM and Avionics measurements, the impedance is always 50
Ω
and cannot be
changed.
Receiving Data Input and Providing Data Output
