Service manual

WLAN TX Measurements
R&S
®
FSV-K91/91n/91ac/91p
38Operating Manual 1176.7649.02 ─ 04
The trigger unit is connected to the DUT and all involved analyzers. Then the trigger
unit can be used in the following operating modes:
●
External mode: If the DUT has a trigger output, the trigger signal from the DUT
triggers all analyzers simultaneously.
The DUT's TRIGGER OUTPUT is connected to the trigger unit's TRIG INPUT con-
nector. Each of the trigger unit's TRIG OUT connectors is connected to one of the
analyzers' TRIGGER INPUT connector.
The trigger unit routes the trigger signal from TRIG INPUT to TRIG OUT 1 to 4, and
thus to the the trigger inputs of the connected analyzers.
●
Free Run mode: This mode is used if no DUT trigger signal is available or the
MIMO signals are simply to be captured at the same (random) time. No connection
to the trigger signal of the DUT is required. The master analyzer sends a trigger
impulse to the trigger unit - via the NOISE SOURCE CONTROL output - to start the
measurement as soon as all slave analyzers are ready to measure.
The NOISE SOURCE CONTROL output of the master analyzer is connected to the
trigger unit's NOISE SOURCE CONTROL input. Each of the trigger unit's TRIG
OUT connectors is connected to one of the analyzers' TRIGGER INPUT connector.
When the master analyzer sends a signal to the trigger unit via its NOISE
SOURCE CONTROL output, the trigger unit triggers all analyzers simultaneously
via its TRIGGER OUTPUTs.
Note: in Free Run mode you have to make sure the TRIG INPUT on the trigger unit
remains open, that is: not connected.
●
Manual mode: a trigger is generated by the trigger unit and triggers all analyzers
simultaneously. No connection to the DUT is required.
Each of the trigger unit's TRIG OUT connectors is connected to one of the ana-
lyzers' TRIGGER INPUT connector. A trigger signal is generated when you press
(release) the "TRIG MANUAL" button on the trigger unit.
Note: in Manual mode you have to make sure the NOISE SOURCE CONTROL
INPUT on the trigger unit remains open, that is: not connected.
A trigger unit is activated in the General Settings.
For more detailed information on the R&S
®
FS-Z11 Trigger Unit and the required con-
nections, see the "R&S
®
FS-Z11 Trigger Unit Manual".
Connecting the R&S
®
FS-Z11 Trigger Unit
Connect the trigger unit with your measurement setup according to the following sche-
matic diagram:
IEEE 802.11n/ac MIMO Measurements