Drake MEQ1000A ASII ASI Input Module - Manual (Page 14)

14 DTA/EAS Considerations and Additional Information
DTA and EAS (EMERGENCY ALERT SYSTEM) CONSIDERATIONS
Any headend using DTAs or EAS (Emergency Alert System) that includes the MEQ1000A must be setup with one EH24A / EH244 /
EH244-IP being the “Master” device and the MEQ1000A and all other additional Drake Headend Products (EH24A / EH244 /
EH244-IP / other additional MEQ1000A) being “Slave” devices.
DTA/E AS CONTROL: The DTA control is used when MEQ1000As are used to supply the QAM signals to DTA set top boxes. It
allows for an ASI stream, generated by a PC to be input to the headend’s Master unit. This control allows for generating
a transport stream that provides a virtual channel map to the DTAs (Known as SCTE 65 tables), and/or provides code updated
to the DTA’s (in a format known as DSM-CC) so that they can be updated through the QAM channel transport stream. The
choices are DISABLED, MASTER (SCTE-18), SLAVE and DEMOD A..
DTA MODE : This menu choice allows the user to activate or deactivate DTA mode. The choices are ENABLE and DISABLE. This
option will only be available when SLAVE is selected under DTA/EAS CONTROL menu.
If DTA MODE is ENABLED, then an ASII module must be present in the Master EH24A / EH244 / EH244-IP to receive
the ASI stream from your PC. W hether it is plugged into Module 5 or Module 6 slot depends on whether the SDE24EAS is
also required in the system or not.
All units at the headend are then daisy-chained through ASI connections.
The Master unit’s ASI OUTPUT connector goes to the ASI INPUT connector of the ASII module in the first Slave unit.
The AS I LOOP output connector of the ASII module in the first Slave unit goes to the ASI INPUT connector of the ASI
module in the next Slave unit.
These ASI LOOPs continue through all Slave units (MEQ1000As, EH24As, EH244s, and EH244-IPs) at the headend.
There can be standard SDE24s in some or all of the remaining slots of the Master unit. If they are wanted to be sent out
on the ASI output of the Master unit, these streams can be picked up from the ASI LOOP output connector of the ASII
module of the last Slave unit in the chain.
VERY IMPORTANT: When the SDE24EAS is used in slot 6 of the Master unit, both encoders in the SDE24EAS
must be set to the lowest encoding bitrate of any other SDE24 in the entire system. This is the only way to make
sure that when the SDE24EAS’ stream replaces the original streams that it will still fit into all the QAM channels.
EAS MODE : EAS Control is provided by 1 of 2 methods:
Method 1 - By using the SDE24EAS module in a “Master” EAS unit (EH24A / EH244 / EH244-IP, but not the MEQ1000A)
as mentioned above. This module has only a single composite input instead of the 2 inputs of a standard SDE24. It is fed
by an external EAS Controller source, that then is encoded by both encoders in the SDE24EAS. W hen EAS is activated,
the transport stream generated by the SDE24EAS is routed internally in the Master unit and replaces the transport
streams coming from the other plugged in SDE24s. This way all MPEG programs coming out of the Master unit have the
EAS video and audio on them. Note that when using this method only one SDE24EAS is required per headend, and is
placed into the Module 6 slot on the rear of the Master EH24A / EH244 / EH244-IP. The MEQ1000A will need to be
placed in the SLAVE setting.
Method 2 - By using the newer digital standard for EAS (known as SCTE 18). In this mode, rather than each MPEG
program being replaced by the EAS video, instead when the EAS is activated, a table is inserted into the transport
stream. This table tells any SCTE 18 capable unit which RF channel to switch to and which MPEG program number to be-
gin decoding. The receiving unit then switches to that program to display the EAS video and audio. W hen the EAS is de-
activated, the receiving unit returns to its original channel.
For Instructions on how to set EAS parameters (including: E AS MODE, EAS RF CHANNEL, EAS MODULATION, EAS MPEG
PROGRAM #, EAS MAJOR CHANNEL, and EAS MINOR CHANNEL), please see instruction manual for the Drake Product
being used as the E AS MASTER UNIT in your headend (EH24A / EH244 / EH244-IP).
DEMOD A MODE :
Allows using DTA/EAS tables while using the MEQ1000A in a drop/add configuration. In order for the DTA/EAS
tables received in the drop/add configuration to be utilized, the DTD1000 must be tuned to an RF channel from the Head
End that contains the desired tables. Otherwise the tables on the PID’s would be missing because they are not
associated with an actual program in the transport stream.