Hamlet 503 EM, Руководство оператора

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11
OPERATING INSTRUCTIONS
DIGITAL ERROR DISPLAY
ST
The signal strength bar is an indication of cable length. It is marked at full and at the
300 metre knee point.
JT
The jitter bar shows the data jitter level, often due to re-clocking of a low level or
noisy signal. It is marked at the zero and knee points.
CR
Displays the number of CRC (Cyclic Redundancy Check) errors, also known as EDH
(Error Detection and Handling). The errors can be selected to cover the full field
including auxiliary data packets or more usually active picture area only. There is an
internal switch for this. The counter counts from 0 to 99 errors and may be reset at
any time by pressing the front panel ERR RST button.
To the right of the CR display are 4 digits representing the checksum of the last
frame, full frame or active picture as selected. For a stationary test card, this will be
a fixed number and is a useful diagnostic aid when the CRC/EDH word of the test
card is known. For moving pictures, the checksum will change with every frame.
Note: CRC/EDH depends on a data packet being sent by the originating equipment. If
the signal source does not support CRC/EDH, ---- is displayed in the CRC area.
CD
Displays the number of code errors. These are due to missing or corrupted TRS
pulses (EAV or SAV). The counter operates as above.
DA
Displays the number of digital audio errors. The signal source can be either
embedded audio or AES/EBU input, selected by an internal switch. If embedded
audio is chosen and no embedded audio packets are present, -- is displayed. The
counter operates as above.
GM
Displays the number of gamut errors. These occur if the digital luminance signal
exceeds peak white or falls below minimum black. Also if the digital colour signals
exceed peak positive or negative. The counter operates as above.
IL
Displays the number of illegal value errors. Illegal values are 3FF and 000. The
counter operates as above.
The number of quantising bits in the data system is also detected and shown in the
error display area as 8 or 10.