ACT 1000 Bedienerhandbuch PDF herunterladen (Seite 5)

DESCRIPTION / INSTALLATION / CONFIGURATION 5

General Description

The R. L. Drake® model ACT1000 is a commer-

cial grade, modular digital headend component pro-

viding 8VSB or QAM input to QAM transmodulation

and RF upconversion in a single unit. Up to 10

ACT1000 modules, along with the required PS151

power supply module, can be installed into a single

RMT150 rack mounting tray, occupying only 2 rack

units (3.5''). The ACT1000 supports ATSC 8VSB and

ITU j.83 Annex B 64QAM and 256QAM inputs, and

outputs an agile ITU j.83 Annex A or B QAM channel.

The ACT1000 supports RF inputs from 54-1002MHz

from an antenna or cable feed. The modulator sup-

ports RF channels from 54-1002MHZ, and all Annex

A and Annex B QAM modes up to 256QAM, includ-

ing all interleaver settings for Annex B.

The transcoder demodulates the desired digital

channel, adapts the bitrate from the input to output

if necessary, and modulates the entire multiplex of

programs on the output channel. PCR values are re-

calculated as required when the input and output bit

rates are not identical, and channel display numbers

(PSIP and MGT/VCT table entries) can be changed.

Installation and Mounting

Install the ACT1000 transcoders into the RMT150

rack frame. Insert each ACT1000 into the frame un-

til the ''F'' connector extends through the front panel

hole, the LED is aligned with the opening in the front

panel, and the hook-shaped projection near the rear

of the ACT1000 engages the rear of the frame. Se-

cure the module into the frame with the supplied ny-

lon washer and 1/2'' ''F'' connector nut.

Connect the supplied power supply cable between

the ACT1000 and the frame-mounted PS151, en-

suring that the correct power supply port is used for

the frame slot location (slot 1 is the left-most slot, as

viewed from the front).

Connect the ACT1000's input signal source to

the front-panel ''F'' connector. Connect the rear-

mounted output ''F'' connector to the output com-

biner as required for the system configuration. En-

sure that the PS151 is plugged into an AC power

source.

When using the RMT150 rack frame, it is not neces-

sary to leave vertical airspace between the frame and

other equipment in the rack, unless other equipment

in the rack specifies minimum gaps. The transcoders

and power supply are designed to provide sufficient

cooling and airflow, even when mounted with adja-

cent RMT150 units above and below.

Configuration

The ACT1000 is controlled primarily via the Drake

model PS151 front-panel interface. The follow-

ing menu options are available for configuring the

ACT1000 (menu name listed in bold, valid settings

listed in fixed-width font):

· IN MODE: VSB-8, QAM-64B, QAM-256B – this

configures the input modulation mode that the

ACT1000 will use

· IN PLAN: OTA, CATV, IRC, HRC – this selects

the channel plan for the receiver section (US off-air,

US standard cable, IRC, or HRC respectively)

· IN CHAN: 1-158 – this selects the input channel

number; the range varies depending upon the chan-

nel plan selected

· ENCODER: ITU-B, ITU-A – this selects the out-

put modulator QAM mode (ITU j.83 Annex B or An-

nex A, respectively); for US cable applications, this

should typically be set to ITU-B

· MODULAT: 256-QAM, 128-QAM, 64-QAM,

32-QAM, 16-QAM – this selects the output mod-

ulator QAM density; only 256- and 64-QAM modes

are available in Annex B

· INTERLV: All ITU interleave modes sup-

ported – this allows the operator to choose a spe-

cific output interleave mode, as necessary (Annex

A mode only supports one interleave mode, as only

one is specified in the standard)

· CLOCK: PRESET, MANUAL – when set to MANUAL

the output symbol rate is continuously variable via

the next setting; when set to PRESET the symbol rate

is fixed at the appropriate bitrate for the modulation

mode chosen

· BD RATE: 1.0000-7.0000 Ms/s – when the

previous setting is configured for MANUAL, this al-

lows the output symbol rate to be configured to an

arbitrary symbol rate. Note that some higher-bitrate

symbol rates may occupy more than 6MHz channel

bandwidth, and that very-low-bitrate symbol rates will

not fill a 6MHz channel

· OUTPUT: NORMAL, STANDBY, CW – changes the

output mode to STANDBY (no output) or CW (a CW

pilot with the correct output power) from NORMAL

· RF OUT: 29.5-45.0dBmV – sets the output power

level of the modulator

· CH PLAN: OTA, CATV, IRC, HRC – sets the

output channel plan in use (US broadcast, US stan-

dard cable TV, IRC, or HRC respectively)

1 2 3 4 5 6 7 8

Kommentare zu diesen Handbüchern

Keine Kommentare

ACT 1000 Bedienerhandbuch Seite 5

Kommentare zu diesen Handbüchern