User manual

System Timing Easysound Stand-alone User Manual
Page 78 Miranda Technologies Ltd
timing adjustment is given a second parameter to allow for the potential
"line" discrepancy.
Timing Adjustment
The timing adjustments available for Easysound Standalone do not affect the
automatic synchronisation of input and output signals. The set-up adjustment
simply controls the value of propagation delay through the Easysound
Standalone.
Where analogue reference is selected an additional parameter providing for a
line correction factor becomes available. The following paragraphs discuss
the adjustments in detail.
Measurement and Test Equipment
The timing adjustments for Easysound Standalone can be accurately set using
either a digital video signal analyser, or a good quality oscilloscope together
with a SDI digital to analogue converter. The following description describes
the use of an oscilloscope and converter to adjust the timing.
SDI BGnd/A Reference
When the SDI A/BGnd input signal has been chosen as a reference, the set-
up display offers an adjustment range where the value of propagation delay
the ranges from "0 lines and 12.025µS" to "0 lines and 63.899µS".
Once the requirement for propagation delay has been determined, the arrow
keys W X are used to set this desired value for Easysound Standalone and the
enter key is used to apply the selection. Where an oscilloscope and digital to
analogue converter is available, the analogue signal at the input and output
should be viewed simultaneously during the adjustment. By expanding the
traces on the oscilloscope, very accurate settings can be achieved.
Where the operation includes use of the B/Fill and/or Key inputs, these inputs
should be checked for their timing position with respect to the A/BGnd input.
Should either signal be early with respect to the A/BGnd input, the maximum
setting for propagation delay is effectively restricted by this period. Although