The next device in the chain is a distribution amplifier (DA)
whichisreceivingitsinputfromtherouter. TheGS9001 device
in the DA will recode the incoming EDH flag as EDA (Error
Detected Already) and pass the IDA flag.
These errors result in the transmission error flags EDH and
EDA and the non-transmission related flags IDH and IDA.
In Figure 9, the AES/EBU audio encoder has generated an
errorduringtheaudioformattingprocessandreportedanIDH
(Internal device error Detected Here) error.
An additional transmission error occurs between the DA and
theproductionswitcherwhichisflaggedasEDH. TheGS9001
in the production switcher now has a list of error flags that can
be reported locally or through a communications interface to
a central maintenance station.
The signal from the audio encoder then experiences
degradation from a faulty cable, before it reaches the router.
In this case, the cable is marginal and is producing random
infrequent errors. A GS9001 device in the router flags these
errors as EDH (Error Detected Here) for Active Picture, Full
Field or both. Incoming IDH flags are also recoded as IDA
(Internal device error Detected Already).
VTR
Transmission
Video
IDH
EDH
Error
IDA
Audio
AUDIO
ROUTER
ENCODE
DA
Transmission
EDA
IDA
Internal Device
Error
Error
Communication
Interface
EDH
EDA
IDA
CENTRAL
MICROPROCESSOR
PRODUCTION
SWITCHER
Fig. 9
VTR
(NO EDH)
Transmission
Error
Video
UES
UES
IDH
IDH
Audio
AUDIO
ENCODE
ROUTER
(NO EDH)
DA
UES
IDA
EDH
Transmission
Error
Internal Device
Error
Communication
Interface
UES
CENTRAL
MICROPROCESSOR
PRODUCTION
SWITCHER
IDA
EDA
EDH
Fig. 10
521 - 38 - 04
13 of 14
GENNUM [ GENNUM CORPORATION ]
