Rohde & Schwarz ZNB20, User Manual

Page: 155 / 1332

Concepts and Features
R&S
®
ZNB/ZNBT
140 User Manual 1173.9163.02 ─ 38
The system error correction data determined in a calibration procedure are stored on
the analyzer. You can read these correction data using the remote control command
[SENSe<Ch>:]CORRection:CDATa
. You can also replace the correction data of the
analyzer by your own correction data sets.
Cal Off label
A label "Cal Off" appears in the trace line if the system error correction no longer
applies to the trace:
This may happen for one of the following reasons:
●
The sweep range is outside the calibrated frequency range.
●
The measurement result is a wave quantity or ratio which is never system error
corrected (see
Chapter 4.1.5, "Data Flow" , on page 85).
●
The channel calibration is not sufficient for the measured quantity (e.g. a one-port
calibration has been performed, but the measured quantity is a transmission
parameter).
●
There is a mismatch between the current Frequency Offset settings and the Fre-
quency Offset settings that were used during calibration (see
"Parallel Measure-
ments with Frequency Offset" on page 82)
●
There is a mismatch between the current sweep mode(s) and the sweep mode(s)
that were used during calibration (see
Chapter 4.1.4.4, "Stepped vs. Swept Mode" ,
on page 84)
●
The system error correction has been switched off deliberately ("User Cal Active" is
disabled).
The analyzer provides other labels to indicate the status of the current calibration; see
Chapter 4.5.4, "Calibration Labels" , on page 158.
Calibration and port de-/activation
The way the analyzer fimware activates/deactivates ports after a successfull calibration
(system error correction or power calibration) has slightly changed:
●
In all FW releases, calibrated ports that were previously disabled, are automatically
enabled as single-ended logical ports.
●
Starting with FW version 2.10, uncalibrated ports were disabled in the related
channel(s). If only one of the physical ports forming a balanced port was calibrated,
the balanced port was dissolved and only the uncalibrated (single-ended) port was
disabled.
In earlier FW versions there was no such port deactivation mechanism.
●
Since FW version 2.40 an uncalibrated port is only disabled if it is not used by a
measurement, i.e. if it is not required by any trace of the related channel.
Calibration