dCS 904 User Manual | Manual for Software Version 1.5x and 1.36 |
dCS Ltd | June 2000 |
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AES3 (AES/EBU) Format
Message HandlingThe AES/EBU interface transmits a data structure that conforms to the dCS version of
•preambles, to allow the receiver to sync up
•up to 24 bits of audio data, transmitted lsb first
•V, a validity bit
•U, a user bit, for the "User Message"
•C, a Channel Status bit, for the "System Message"
•P, a parity bit
The default AES/EBU message attached to the output data by the unit before being changed by the user is as follows:
Professional:On
Mode:Stereophonic
Source:DCS1
Destination:null
For more information on the way dCS implement the AES3 system message to handle higher sample rates, see the Appendix to this manual. For the formal definition of the AES3 interface, see footnote9, from the AES.
How Far will it Go?The AES/EBU format was designed to go reasonable distances, at 44.1 kS/s and 48 kS/s. Figure 27 and Figure 28 below show it over 16 m and 94 m using average cables. The waveform at 94 m can still be decoded, although it is quite degraded. Cable delay is about 5.6 nsecs/metre.
At 96 kS/s (twice the data rate the format was designed for) the allowed cable length is less. Figure 29 and Figure 30 below show this over 16 m and 94 m. At 16 m the waveforms are still very good, but at 94 m they are really quite unreliable.
We recommend restricting 96 kS/s cable runs to 20 m or less, and using good cable near this length.
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Manual part no: DOC135904 iss 2B2 | Page 47 | 135904ma2b2.pdf file available from website |
Contact dCS on + 44 1799 531 999 | email to: more@dcsltd.co.uk |
(inside the UK replace + 44 with 0) | web site: www.dcsltd.co.uk |