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Technical References
Error reporting
Errors are repor ted in five different ways:
• Error detected here, edh
• Error detected already, eda
• Unknown error status, ues
• Internal error detected here, idh
• Internal error detected already, ida
The last two reports, idh and ida, are used when a piece of equipment has the capability to
check for data corruption between its input and output.
EDH actually checks and reports each video frame in three ways, calculating separate check
sums for the complete frame, the active picture area and the ancillary area. (The ancillary area
is the area of the frame blanking interval that can contain digital audio signals and other
multiplexed information.) A reason for this division of areas is so that errors in the active picture
area can be given a higher fault priority, simply because they have direct effect on the program
audience.
Sony is supporting EDH, and an increasing number of relevant products(down to board level in
some cases) now have the ability to provide a visual eda report with an LED indicator.
EDH and ISR
In an overall system, EDH-equipped devices can report to a computer network, with status
indication displayed by a PC. EDH is complementary to the well-established Sony ISR
(Interactive Status Reporting) system, which can be used to report EDH status checks. In this
way, detailed information on the per for mance of individual pieces of equipment is combined
with information on the per formance of their interconnections.
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