Drake EH24A/EH24A ASI - Manual (Page 6)

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General Description
EH24A
The Drake model EH24A, encoder host, is the core multiplexer, QAM modulator, up-converter, ASI output, user interface,
and power supply for the SDE24/SDE24A, HDE24, and SDI24A encoder modules. Up to six encoder modules can be
installed into the EH24A via rear panel access. SDE24/SDE24A encoders can encode one or two programs, depending on
whether MPEG2 or MPEG4/H.264 encoding is used (see below), per module. Typical applications are to provide MPEG
video in MDUs, medical facilities, libraries, stadium video networks, private cable and other QAM applications. The
EH24A may be used in Edge or headend applications. There are two multiplexers in the EH24A, one providing an ASI
output stream and one providing a stream to the built in QAM modulator/upconverter. The latest firmware release
provides EAS implementation and allows low speed data streams to be added to the output for purposes such as DTA
channel mapping and code upload.
SDE24/SDE24A
Each SDE24 module contains two encoders and if MPEG2 encoding is desired for two programs, two MPEG2
transport streams can be generated. If MPEG4, H.264 encoding is desired, each SDE24 module can encode one
program to an H.264 output stream. Another option is to encode one program in MPEG2 and the second program
in H.264. The SDE24/SDE24A accepts either NTSC or PAL video inputs. The SDE24A is capable of MPEG4, H.264 encoding
in both inputs if desired.
***IMPORTANT NOTICE***
When installing the SDE24A in a EH24A chassis (stock # 1002510A), the EH24A must have firmware version 3.0 or
higher. Should you require any technical assistance, please contact DRAKE Service at (937) 746-6990.
SDE24EAS
This is a specialized version of the SDE24/SDE24A to be used, when EAS is needed, to encode the EAS
program. EAS mode is provided by one of 2 methods, or both.
1) By installing the SDE24EAS module in slot 6 of the EH24A. This module has only a single composite input instead of
the two inputs of the standard SDE24/SDE24A. It’s video and audio input will be provided by an external EAS contoller
providing a NTSC composite alert message. When EAS is activated, the transport stream, created by the SDE24EAS,
replaces the transport streams that were coming from the other encoder modules in the EH24A. All programs will
then become the EAS alert program. Only one SDE24EAS is required per headend. The alert can be encoded in
either MPEG2 or MPEG4/H.264. All programs will be the same.
2) SCTE18 mode. In this mode, when an EAS alert is activated, the EH24A will place the SCTE18 table into the transport
stream. The SDE24EAS will encode the alert program. SCTE18 capable receivers are told where to tune.