R&S 1129.7246.03, Operating Manual

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R&S ESU Instrument Functions
User Port
4.372 Operating Manual 1302.6163.12 - 03
4.15 User Port
The user port is located at the rear panel of the R&S ESU. For information on the
mechanical design and the electrical characteristics refer to the Quick Start Guide,
chapter
1 , “Front and Rear Panel” .
An essential performance criterion to be met by automatic test systems is to mini-
mize the time overhead of the entire test relative to the net measurement time. A
typical test comprises the following steps:
1. Setting of R&S ESU (frequency, level, bandwidth, measurement time, trigger
source)
2. Setting of device under test (DUT) and activation of its output signal
3. Start of measurement; R&S ESU waits for trigger signal
4. Generation of trigger signal; test system waits for ready signal from R&S ESU
5. Reading of measured data
After the start of a measurement, hardware settling times are allowed for the
R&S ESU before data acquisition is started. Trigger signals received by the
R&S ESU during the settling time will, therefore, be ignored.
This behavior is not critical in most cases, as long as the trigger signal is periodic
and the test signal is stationary.
Fig. 4.37 Test with stationary test signal and periodic trigger signal
In the above case, the R&S ESU will respond to the first trigger signal received after
the settling time.
The situation is quite different, however, if data acquisition is to be started by a sin-
gle trigger event. In such a case it is mandatory that settling times have elapsed
before the trigger signal is sent. Otherwise, the trigger signal will not be identified as
a request for data acquisition, and the subsequent query of measured data will
result in a time-out on the controller:
Analyzer Setup
Analyzer Settling Time
DUT Output Signal
Start of
Measurement
Data Acquisition
Trigger
Signal
Trigger Signal Accepted by
Analyzer