Drake MEQ1000A ASII ASI Input Module - Manual (Page 11)

Setup and Programming (Continued) 11
If INPUT B is selected, the B program is used and A filtered
out. If INPUT A+B is chosen, then both are accepted if
present.
Note: It is OK to use this menu to set up desired program
selections 'off line'. That is, with no actual input at the
present time. Programs may be selected that may not
currently be in the input stream but are desired at some
future time.
Note: It is possible to select both programs with the same
program number - one from A and one from B as long as
the INPUT B offset is set so that the B program number plus
the offset amount does not duplicate a program number
from the A input. The offset is not included in the MPEG
program number display being discussed above but the
offset will be added to all MPEG program numbers from the
B input when they are added to the output multiplex.
PSIP: This menu provides a choice of how the unit
organizes the PSIP information from two ATSC streams that
are being multiplexed.
In the ENABLED setting, information from the MGT and
VCT tables from both signals will be used to build a new
table for the combined output signal. Both input streams
must have these tables present in order for the unit to be
able to perform this operation. EIT tables will be processed
so as to provide program information, if present, for the next
12 hours. This selection is the only one that passes EIT
table program information to the multiplexed output signal.
RRT and S TT tables from Demod A are passed through.
If the broadcast station is not transmitting complete MGT and
VCT tables, the ENABLED selection cannot be used. In this
situation, DISABLED may be selected. In DISABLED mode,
the unit does not process or output any MGT, VCT, or EIT
tables. This can be a fine solution for cable systems
that use set top boxes which operate from their own system
channel map and have no need for these tables. MPEG
program information is still processed. Some retail consumer
QAM set tops operate perfectly in this mode and
others may not.
The third option is the BASIC MGT, VCT choice. W hen this
selection is made, the DQT1000 or MQM1000 will build its
own MGT and VCT tables from the incoming streams even
if one or both of the streams do not contain these tables.
This solution should satisfy all types of set top boxes but
will not provide any EIT table program guide information.
The S TT and RRT tables from the source are passed
through unchanged in the ENABLED mode and filtered out
in the other modes.
VCT TABLE : This menu is only available when ENABLED
or BASIC MGT, VCT has been selected in the previous
PSIP menu. You may select the TVCT - TV channel table or
CVCT table for CATV. Usually the TVCT choice must be
selected for ATSC input signals.
MAJOR CHANNEL: This menu is not available if PSIP is
disabled. This setting will determine how a channel number
is displayed on a consumer TV if the TV is tuning the output
of the MEQ1000A without a cable box.
W hen ORIGINAL is selected, the major channel number
indicated in the output tables will be that sent by the original
broadcaster. If OUTPUT CHANNEL is selected, the major
channel number will be set to the channel number of the
MEQ1000A RF output channel. W hen a cable box is used, it
usually does not require or use this information.
Minor channel numbers are the same as those input via
module A and as input via module B with the offset added to
the B side programs.
W hen USER DEFINED is selected and the remote control
software is used to allow programming via a PC, then the
MPEG program number and the major and minor virtual
channel numbers may be set to whatever number the
operator chooses providing total flexibility. These numbers
cannot be programmed with the front panel buttons but only
via a PC and the RS232 interface of the MEQ1000A.
It is up to the operator to insure that no duplications are
made when using this mode.
QAM MODE : This menu allows the user to set the modulation
type for the output. Choices range from 16-QAM
through 256-QAM. 'A' suffixes indicate DVB compliant FEC
and the 'B' suffixes indicate DigiCipher II FEC encoding.
Note that when using the MEQ1000A in the multiplex mode,
the output QAM mode usually must be 256-QAM. For CATV
systems using DigiCipher II, select the QAM-256B mode.
For DISH Network QAM distribution or other DVB systems
using DVB set tops, choose the QAM-256A mode.
W hen used for a single input processing function, choose
the output mode accordingly from any of the available
options that will provide a high enough data rate.
GRAY ENCODING: This menu is only available when QAM
modes QAM-16A through QAM-1024A, are selected. The
choices are DVB and DAVIC. Gray Encoding is normally not
used for video data.
QAM SYMRATE : Preset or Manual: If PRESET is
selected, the symbol rate will be automatically set to the
‘normal’ rate based on the QAM mode that is selected and
assuming a 6 MHz wide QAM channel. If MANUAL is
selected, pressing the right or left arrow buttons will allow
selection of symrates from 1.000 thru 7.000 MSym/Sec
using the up and down arrow buttons.
QAM SYMRATE : This menu allows selection of the output
QAM baudrate or symbol rate. Set as required by the set
top box. W hen multiplexing two ATSC input signals, in
DigiCipher II, 256-QAM CATV systems, this is usually
5.3606 Ms/s. In DVB systems, the rate would be 5.264
Ms/s. In any case, the rate must be high enough to provide
a data bitrate of at least 38.81 Mbps (do not confuse this
with the symbol rate). If the set top box requires a fixed
higher rate, this may be manually set.