Timewave DSP-232, Operating Manual

Page: 147 / 271

Chapter 8 ASCII and Baudot Operation
Baudot RTTY operation is very common around the world and is the basis of the TELEX network and most radio
press, weather and point-to-point message services. The Baudot/Murray and ITA #2 character sets don’t contain
lower-case or the special punctuation and control characters found in ASCII.
Because the Baudot/ITA #2 code requires only five information bits to define each character, it will generally suffer
fewer errors than ASCII code at the same data rate.
BItinv
n Default: $00
Mode: RTTY Host: BI
“
n ” 0 to $1F, (0 to 31 decimal) specifies a number to be exclusive-ORed with every received Baudot character.
BITINV 0 is plain text.
Bit inversion is used to prevent listeners from reading some commercial Baudot transmissions. Usually either 2 or 3
bits of each character are inverted to give the appearance of an encrypted transmission. Try different settings of
BITINV on a Baudot signal after the baud rate has been determined and experimenting with the 5BIT command.
CODe
n Default: 0 (International)
Mode: Baudot RTTY, Morse, AMTOR Host: C1
“
n ” 0 to 6 specifies a code from the list below. (RX = Receive; TX = Transmit)
CODE Meaning Morse Baudot AMTOR PACKET
0 International RX/TX RX/TX RX/TX
1 US teleprinter RX/TX RX/TX
2 Cyrillic RX RX/TX RX/TX
3 Transliterated Cyrillic RX RX RX
4 Katakana RX/TX
5 Transliterated Katakana RX
6 European RX RX
Not all the codes in the list above can be transmitted.
NOTE: FCC Part 97.69 and 97.131 calls for the use of (
CODE 0 ) “International Telegraph Alphabet Number 2”
five unit teleprinter code. The Baudot characters “$”, “#” and “&” are not permitted for use by US Amateurs.
CODE 0 : International
In Morse, this means the International Morse Code. For Baudot and AMTOR, this means the ITA #2 teleprinter
code, which is internationally recommended for Baudot and ’TOR communications and shown below:
lowercase set UPPERCASE SET
1 2 3 4 5 6 7 8 9 0 - = ? ? ? ? ? ? ? ? ( ) ? +
Q W E R T Y U I O P ? ? Q W E R T Y U I O P ? ?
A S D F G H J K L ? ’ A S D F G H J K L : ?
Z X C V B N M , . / Z X C V B N M , . ?
The following special Morse characters are available as receive only and are used in non-English Morse alphabets.
Morse RX
----
ch
-.-..
c
.-..- e
--..-
z
--.--
ñ
September, 05 8-9