User manual

Easysound Stand-alone User Manual System Timing
Miranda Technologies Ltd Page 77
System Timing
This final part of the section describes the way in which signals applied to,
processed by and output from, Easysound Standalone are synchronised.
Propagation delays through the unit are discussed and the method used to
adjust and set this particular type of delay is detailed.
To obtain the highest standard of performance from the Miranda
Technologies Ltd Easysound Standalone it is highly recommended that the
user be acquainted with the concepts of synchronisation and timing. An
understanding of the timing relationships within the Miranda Technologies
Ltd Easysound Standalone and the equipment with which it interfaces,
enables the user to determine the optimum timing of the overall system.
Overview
Where signals from more than one source are to be processed, it is essential
that these signals are precisely synchronised and perfectly in-phase, prior to
processing. Within certain specified tolerances, described later, Easysound
Standalone is able to automatically re-synchronise the signals that are applied
to its three signal inputs.
As signals pass through Easysound Standalone, or any other equipment, they
are unavoidably subjected to a propagation delay. The value of the delay may
vary depending on the mode configuration of the unit. Rather than exhibiting
a non-quantifiable propagation delay, Easysound Standalone is provided with
a timing adjustment that enables the integrator or user to set a specifically
determined propagation delay through the unit. This timing adjustment may
be used to match an Easysound Standalone to the propagation delays of other
Easysound Standalones or of other broadcast equipment.
Miranda Technologies Ltd always recommends the use of a separate
analogue, "Black and Burst", reference signal for timing all the equipment
within a system. Where this method of timing is used, it is common for the
reference source to be located some distance from the Easysound Standalone
and it is possible that the synchronisation of the SDI input signals and the
"Black and Burst" reference may be displaced by several video "lines".
Where this preferred form of timing is chosen the Easysound Standalone