- •59 Telex communications
- •59.1 Introduction
- •59.2 Characteristics of telex
- •59.3 Telex signalling
- •59.3.1 Single current signalling
- •59.3.2 Double current signalling
- •59.3.3 Single channel voice frequency signalling
- •59.3.4 Type a and Type b signalling
- •59.4 Answerback
- •59.5 Telex protocol
- •59.6 Telex terminals
- •1. Learn the words & word combinations:
- •2. Read the text «Telex Communications».
- •3 Answer the following questions:
- •4. Retell the text according to your plan
- •5. Make a short report about three major signalling systems being in use throughout the world
- •6. Make a written translation of two passages about «Telex Protocol» (59.5)
59.5 Telex protocol
As telex signalling is machine to machine operation and the distant end may be unattended, then a protocol has been established. Several exist hut the ones given in Table 59.1 are generally internationally understood. All telex messages should commence with the sender's answerback so that the distant end can easily find the caller. The sequence of setting up a call on the telex network is seizing the line, receiving call confirmation and proceed to select indication from the telex network. The telex terminal then transmits the address information and if the call set up is successful the distant machine will automatically transmit to the caller the answerback code indicating it is ready to accept the message. If the call is unsuccessful for any reason the failure will be indicated by a service code of up to 3 letters transmitted from the telex network to the originating machine and printed out on the local record of the telex message.
The telex network has facilities for testing the telex lines and can detect if a machine has its power disconnected or the line is out of order, and then send the corresponding service message from the network to the originating machine.
Figure 59.5 Type A and B signalling
59.6 Telex terminals
Modern telex terminals are highly sophisticated pieces of equipment built around the principles of the personal computer. They comprise a microprocessor, disk drive, keyboard, VDU, and heavy duly printer with paper roll holder. These machines are still required to interwork with the older electromechanical machines, or paper tape transmitters or receivers, that exist on the telex networks. The modern telex terminal has in addition the ability to communicate with the telex network word processing software, to enable the telex operator to prepare messages, edit, store and finally transmit the messages. This makes the telex terminal a very powerful communication tool for business use.
Table59.l Telex protocol ( indicates some of the typical service codes)
1. Learn the words & word combinations:
Telex message |
Телексное сообщение |
Manual (operator) switchboard |
Ручной коммутатор |
Handsending |
Отправка вручную |
To acknowledge |
Подтверждать прием, квитировать |
Local record |
Локальная запись |
Duplicate |
Снимать копию, копировать |
Unattended |
Несопровождаемый, без внимания |
A character set |
Набор знаков, набор символов |
Teleprinter |
Телетайп, стартстопный телеграфный аппарат |
Shift character |
Знак (символ) смены регистра |
Figures shift |
Установка регистра цифр |
Letters shift |
Установка регистра букв |
Code conversion |
Преобразование кода, перекодировка |
Voce frequency |
Тональная частота |
Telex exchange |
Станция телексной связи |
Double current signaling |
Телеграфирование на 2-х фазном токе |
Single current signaling |
Телеграфирование на 1-фазном токе |
Full duplex |
Дуплексный (двусторонний) режим Дуплексная (одновременная двусторонняя) связь |
Half duplex |
Полудуплексная (поочередная двусторонняя) связь |
Invariably |
Неизменный |
Feed |
Питание, подпитка |
Magnitude |
Величина, значение (величины) |
Inherent(ly) |
Присущий |
Frequency allocation |
Распределение частоты |
Frequency-shift signaling |
Частотно-манипулированный сигнал |
Baud |
Бод (единица скорости передачи информации) |
To evolve |
Развиваться |
Address signal |
Сигнал адресации |
Dial pulse |
Импульс набора номера |
Answerback |
Ответ (в протоколе передачи данных); автоответ; реакция на сигнал дистанционного управления. |
Answerback code |
Код автоответчика |
Trigger |
Триггер; запускающий сигнал |
Trigger |
Запускать, инициировать, включать |
VDU – video display unit |
Дисплей, видеомонитор |
Heavy duty |
С тяжелым режимом работы; с высокой нагрузкой; мощный |
Paper roll holder |
Держатель бумажного рулона |
Word processing software |
ПО пословной обработки; ПО обработки текстов |