Wavetek ANT-20, Operating Manual

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ANT-20/ANT-20E Broadband Analyzer/Generator
Operation O-1
Operation
1 ATM Test Control
1.1 Introduction
Task
The “ATM Test Control” VI is used to select a test type and to configure the instrument for the
selected test type. You can also control the running of the test from this VI if the selected test
type allows for manual control (“Test - Online Control” dialog). Each test type generally includes
configuration of the generator and the receiver.
The instrument configuration covers selection of the port configuration (topology), setting the
various protocol layers, in particular the ATM layer and higher layers, as well as selection of the
type of connection, i.e. “permanent” or “switched”.
The “test types” available for selection are used to structure measurement types and connection
modes. These are arranged according to protocol layers, with only the ATM layer being
supported at present. Only those test types that are possible and practicable with the selected
instrument configuration are available for selection.
On-line control allows relevant test parameters to be altered during the traffic generation. This
is particularly useful for traffic parameters such as the peak cell rate or mean cell rate, allowing
rapid assessment of the effects of these parameters on the behavior of the device under test.
On-line control also allows errors (anomalies and defects) to be inserted into the test cell
stream.
The “ATM Test Control” VI is normally used together with the “ATM Test Results” VI. The latter
displays the test results as determined by the selected test type and corresponding instrument
configuration.
The settings made for a certain test type are saved within an “application” and are set again
automatically when the test is called up again. Bit error measurements in the physical layer are
not supported by the “ATM Test Control” VI.
Requirements
✓
The “Signal Structure” VI must also be loaded when performing ATM measurements. This is
used to control and configure the physical layer, e.g. select the bit rate, frame type, etc. The
instrument can also be configured for bit error measurements in the physical layer with the
“Signal Structure” VI. If the “ATM Test Control” VI is loaded, the “Signal Structure” VI can
only be accessed via the “Instrument Configuration” dialog of the “ATM Test Control” VI.
✓
To perform detailed tests in the physical layer, the “Anomaly/Defect Insertion” and “Anomaly/
Defect Analyzer” VIs should also be loaded. The “Anomaly/Defect Insertion” VI allows
insertion of a wide range of anomalies and defects in the physical layer. The “Anomaly/
Defect Analyzer” VI provides corresponding analysis of the anomalies and defects in the
physical layer.