AT&T Bell System 402D Series Description And Operation

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BELL SYSTEM PRACTICES
AT&TCo Standard
SECTION 594-020-100
Issue 3, January 1972
DAT A SET 402D-TYPE
RECEIVER
DESCRIPTION AND OPERATION
CONTENTS
1.
GENERAL
. . . . .
2.
PHYSICAL DESCRIPTION
3.
FUNCTIONAL DESCRIPTION
4.
OPERATION
5. REFERENCES
1. GENERAL
PAGE
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1.01
This section includes description and operation
information on Data Set (DS) 402D-type. It
does not contain operating information for the
business machine associated with the data set.
1.02
This section is reissued:
• To add information on the use of DS 402D-type
with Key Telephone Systems
• To comply with present format
• To provide a functional description.
Since this is a general revision, change arrows
have been omitted.
1.03
DS 402D3 and D4 provide the same features
as their counterparts, DS 402Dl and D2,
and provide an additional feature which makes
possible their alternate use with a TOUCH-TONE@
telephone that functions as a data transmitter.
Information pertaining to DS 402Dl and D2, which
have been Manufacture Discontinued, will be retained
since many of these data sets are used in the field.
1.04
DS 402D-type is the receiver component of
the 402 Data System and receives signals
from a 402A or 402C transmitter.
It provides
eight parallel binary channels for data transmission.
The range of frequencies is shown in Table A. A
ninth channel is provided for timing information
which allows asynchronous operation at any speed
up to 7 5 characters per second.
1.05
DS 402D-type is designed primarily for use
on the switched telephone network; however,
it can be used on private lines. It is installed with
a DS 402C-type when a transmit-receive terminal
is desired and with Data Auxiliary Set (DAS)
804A-type for a receive-only terminal. Keys on
the DAS 804A or DS 402C are used for attended
control of the station.
1.06
Refer to sections on DS 402C-type for
information concerning the transmitter_ and
sections on DAS 804A-type for information concerning
the attendant station.
TABLE A
CHANNEL
Mark
Freq Hz
Space
FREQUENCY RANGE- DATA CHANNELS
1 2 3 4
TIMING 5
730 900 1070
1240
1410 1580
800 970 1140 1310
1480
1650
© American Telephone and Telegraph Company, 1972
Printed in U.S.A.
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