User manual

Installation and Integration Imagestore User Manual
Page 202 Miranda Technologies Ltd
Measurement and Test Equipment
The timing adjustments for Imagestore 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 minimum value of
propagation delay is restricted dependant on the Imagestore installed options.
Where EasySound is not installed, the range of adjustment for propagation
delay available is restricted to values ranging from "0 lines and 2.590µS" to
"0 lines and 63.899µS". Where EasySound is installed, the minimum
propagation delay adjustment is higher and the range available is "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 Imagestore 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
the Imagestore will permit settings in excess of the maximum permissible,
the effective adjustment limit is reduced accordingly.
For example, if the B/FILL signal were found to be 5µS early with respect to
A/BGnd, then the true valid adjustment range, without EasySound, is reduced
to "0 lines and 2.590µS" and "0 lines and 58.899µS".
If either signal is late with respect to the A/BGnd input then the lower
propagation delay limit value is effectively increased accordingly. For
example, if Key is 5µS late and B/FILL is 5µS early, with respect to A/BGnd