Drake MEQ1000A Multiplexing Hybrid QAM Modulator - Manual (Page 11)

Setup and Programming (Continued) 11
If INPU T B is s elec ted, the B program is us ed and A filtered
out. If INPU T A+B is c hos en, then both are acc epted if
pres ent.
Note: It is OK to us e this menu to s et up des ired program
s elec tions 'off line'. That is , w ith no actual input at the
pres ent tim e. Programs m ay be selected that m ay not
c urrently be in the input s tream but are desired at s om e
future tim e.
Note: It is poss ible to s elec t both programs w ith the s ame
program num ber - one from A and one from B as long as
the INPU T B offs et is s et s o that the B program num ber plus
the offs et am ount does not duplic ate a program num ber
from the A input. The offs et is not inc luded in the MPEG
program num ber dis play being disc uss ed above but the
offs et will be added to all MPEG program numbers from the
B input w hen they are added to the output m ultiplex.
PSIP: This menu provides a c hoic e of how the unit
organizes the PSIP inform ation from tw o ATSC s tream s that
are being m ultiplexed.
In the ENABLED s etting, inform ation from the MGT and
VCT tables from both signals will be us ed to build a new
table for the c om bined output signal. Both input s treams
m us t have thes e tables pres ent in order for the unit to be
able to perform this operation. EIT tables w ill be proc ess ed
s o as to provide program inform ation, if pres ent, for the next
12 hours . This s elec tion is the only one that pass es EIT
table program inform ation to the m ultiplexed output s ignal.
RRT and S TT tables from Dem od A are pass ed through.
If the broadc as t s tation is not transmitting c om plete MGT and
VCT tables , the ENABLED s elec tion c annot be us ed. In this
s ituation, DISABLED may be s elec ted. In DISABLED mode,
the unit does not proc ess or output any MGT, VC T, or E IT
tables . This c an be a fine s olution for c able s ystems
that us e s et top boxes w hic h operate from their ow n s ys tem
c hannel map and have no need for thes e tables. MPEG
program inform ation is s till proc ess ed. Some retail c ons um er
QAM s et tops operate perfec tly in this m ode and
others m ay not.
The third option is the BASIC MG T, VC T c hoic e. W hen this
s elec tion is made, the MEQ1000 will build its ow n MGT
and VCT tables from the incom ing s treams even if one or
both of the s treams do not c ontain thes e tables . This
s olution s hould s atis fy all types of s et top boxes but
w ill not provide any EIT table program guide inform ation.
The S TT and RR T tables from the s ource are pass ed
through unc hanged in the ENABLED m ode and filtered out
in the other m odes .
VCT TABLE : This menu is only available w hen ENABLED
or BASIC MG T, VC T has been s elec ted in the previous
PSIP m enu. You m ay s elec t the TVCT - TV c hannel table or
CVCT table for CA TV. Us ually the TVC T c hoic e m us t be
s elec ted for ATSC input s ignals .
MAJOR CH ANNEL : This m enu is not available if PSIP is
dis abled. This s etting will determ ine how a c hannel num ber
is dis played on a c ons um er TV if the TV is tuning the output
of the MEQ1000A without a c able box.
W hen ORIGINAL is s elec ted, the m ajor c hannel num ber
indic ated in the output tables w ill be that s ent by the original
broadc as ter. If OUTPU T CHANNEL is s elected, the m ajor
c hannel num ber w ill be s et to the c hannel num ber of the
MEQ1000A RF output c hannel. W hen a c able box is us ed, it
us ually does not require or us e this inform ation.
Minor c hannel numbers are the s am e as those input via
m odule A and as input via m odule B with the offs et added to
the B side program s.
W hen USER DEFINED is s elec ted and the rem ote c ontrol
s oftw are is us ed to allow programm ing via a PC, then the
MPEG program number and the m ajor and minor virtual
c hannel num bers may be s et to w hatever num ber the
operator c hoos es providing total flexibility. Thes e num bers
c annot be programm ed w ith the front panel buttons but only
via a PC and the RS232 interfac e of the MEQ1000A.
It is up to the operator to ins ure that no duplic ations are
m ade when using this mode.
QAM MODE : This menu allow s the us er to s et the m odulation
type for the output. Choic es range from 16-QAM
through 256-QAM. 'A' s uffixes indicate DVB c om pliant FEC
and the 'B' s uffixes indic ate DigiCipher II FEC enc oding.
Note that w hen us ing the MEQ1000A in the m ultiplex m ode,
the output QAM m ode us ually mus t be 256-QAM. For CATV
s ys tems us ing DigiCipher II, s elec t the QAM-256B m ode.
For DISH Netw ork QAM dis tribution or other DVB s ys tems
us ing DVB set tops , c hoos e the QAM-256A m ode.
W hen us ed for a single input proc ess ing function, c hoos e
the output m ode ac cordingly from any of the available
options that will provide a high enough data rate.
GRAY ENCODING : This m enu is only available w hen QAM
m odes QAM-16A through QAM-1024A, are s elec ted. The
c hoic es are DVB and DAVIC. Gray Enc oding is norm ally not
us ed for video data.
QAM SYMR ATE : Pres et or Manual: If PRESE T is
s elec ted, the s ymbol rate will be autom atically set to the
‘normal’ rate bas ed on the QAM m ode that is s elec ted and
ass uming a 6 MHz w ide QAM c hannel. If MANUAL is
s elec ted, press ing the right or left arrow buttons w ill allow
s elec tion of s ym rates from 1.000 thru 7.000 MSym /Sec
us ing the up and dow n arrow buttons .
QAM SYMR ATE : This m enu allow s s elec tion of the output
QAM baudrate or s ym bol rate. Set as required by the s et
top box. W hen m ultiplexing tw o ATSC input s ignals, in
DigiCipher II, 256-QAM CA TV s ys tems , this is us ually
5.3606 Ms /s . In DVB s ys tems , the rate w ould be 5.264
Ms /s . In any c as e, the rate m ust be high enough to provide
a data bitrate of at leas t 38.81 Mbps (do not c onfus e this
w ith the s ym bol rate). If the s et top box requires a fixed
higher rate, this may be m anually s et.