Function Reference
TELETEXT
5
5-3
TELETEXT
General
Instruments with the Teletext and Wide Screen Signalling (WSS) option offer Teletext B
(UK-Teletext, CCIR system B) and Teletext A (France, CCIR system A). Teletext B in-
cludes the FLOF/FASTTEXT (Full Level One Feature), TOP (Table Of Pages), and VPT
(Video Recorder Programming by Teletext) or PSF (PDC Preselection Function).
Teletext A offers the DIDON Antiope Teletext system.
Teletext is an additional information service being offered by many TV broadcasters us-
ing the normal TV channels. During distinct lines in the vertical blanking period, the
teletext data are serially transmitted and are invisible in the normal picture. The data are
stored in the memory of the teletext decoder of the TV or the VCR and can be called up
by page number or subject using the remote control. Operation and memory capacity for
instruments with teletext have been improved and extended in the last few years.
UK-Teletext
A teletext page consists of a maximum of 24 rows, each of which can contain 40 charac-
ters. The first text row, the page header, may contain information such as page number,
time, and date. The data transmitted in a TV line correspond to the text row of a page. For
transmitting teletext data, 8-bit words are used, consisting of seven information bits and
one parity bit.
Teletext information can be transmitted in lines 7 to 22 for the first field, and in lines 320
to 335 for the second field. Fluke 54200 generates the Teletext B in lines 13, 14, 20, 21
and 326, 327, 333, 334 (8 line mode) but can be changed to lines 20, 21, 333, and 334. In
the Antiope system the text data are generated only in lines 20, 21, 333, and 334 (4 line
mode). For further information about position and levels of a teletext data line, see
Figure
5-1
.
For TOP and FLOF/FASTEXT, another menu line, text line 25 at the lower border of the
TV screen, is transmitted. For older TVs with teletext but without the TOP/FLOF func-
tion, this additional information is ignored.
TOP (Table of Pages)
TOP teletext is an extended teletext service that can be received using a TOP teletext
decoder. TOP improves the speed and ease of access to teletext. In Germany most broad-
casters transmit the TOP teletext.
The teletext pages are grouped according to subjects. The menu line at the bottom of the
screen contains additional information that is selected using the colored keys of the remote
control. In some teletext decoders, these teletext pages are stored in memory; so they are
immediately available. The special colored keys on the remote control provide the follow-
ing functions:
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