OmniTek Ultra 4K Tool Box, Руководство пользователя

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Ultra v2.0a User Guide
S-1
S : Eye & Jitter Measurement
This section describes the tools the Omnitek
Ultra
provides for assessing video integrity of SDI
video transmissions and for locating sources of jitter. To analyse any SDI video signal up to and
including 6G-SDI, the system you use will need to include the PHY option, together with any
VIDEO_ xx options that are needed to support the video standards that you wish to analyse. To
analyse 12G-SDI, the system you use will need to include both the PHY option and the PHY_ADV
option, as well as the VIDEO_12G option.
The PHY_ADV option is also needed alongside the PHY option in order to take advantage of the
Jitter Spectrum and Jitter Histogram displays.
Figure S-1:
Eye Waveform display
S.1 Overview
The various measurements and assessments discussed in this section result from analysis of the
carrier of an SDI video transmission.
The characteristics of this analogue signal are determined through time equivalent sampling. After
an initial set-up period in which the sampling builds up sufficient data, it becomes possible to
determine parameters such as the signal amplitude, the unit interval, the rise time and the fall time
of the signal, together with information about the level of jitter in the signal. It is also possible to
identify the waveband in which jitter occurs, which can help in identifying its source.
These are all parameters that affect the integrity of any transmission and ultimately whether the
receiver will be able to interpret the signal sufficiently accurately to display the desired images.
Most of them are also subject to limits imposed by transmission standards.
The analysis of the carrier signal is carried out by the
Ultra ’s integrated Physical Layer Analyser,
the input to which is a dedicated ‘Eye’ SDI port on the back of the instrument (see ‘Set-Up below).
The data gathered is used both to generate an Eye Waveform plus a range of Jitter displays, and to
determine the basic signal amplitude, rise-time etc. parameters. Some of these parameters are
displayed alongside the Eye and Jitter displays: additional status information can be found from
the Status displays (see Section O).