AT&T Bell System 401E Series Description And Operation

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BELL SYSTEM PRACTICES
AT&TCo Standard
SECTION 594-014-100
Issue 6, February1973
DATA SET 401~-TYPE
TRANSMITTER
DESCRIPTION AND OPERATION
CONTENTS
1. GENERAL
2. PHYSICAL DESCRIPTION
3. FUNCTIONAL DESCRIPTION
PAGE
2
of contact closures. These closures are converted
to voice-frequency tones and transmitted over the
telephone line. The data set at the receiving station
converts the voice-frequency tones back into contact
closures and delivers them across the interface to
the receiving business machine.
1.05
Both rotary dial (data sets 401El, 401E2,
4. OPERATION
.
4
and 401E3) and TOUCH-TONE@ (data sets
401E4 and 401E5) versions of the data sets are
5. REFERENCES 6
provided. Data set 401E4 is similar to data set
401E2, and data set 401E5 is similar to data set
401E3.
1. GENERAL
1.01
This section provides the description and
operation information on data set 401E-type
(MD). It does not include information concerning
the business machine used with the data set.
1.02
This section is reissued for the following
reasons.
• To describe option M of data sets 401E2
and 401E4.
• To delete cover removal and replacement
instructions. This information can be found
in Section 594-014-200.
• To add a reference section.
1.03
Data set 401E-type is designed primarily
for use in DATA-PHONE@ service. It
provides one-way transmission of alphanumeric
information over the DDD network or 2-wire private
lines. The 401E is a 3-out-of-14 multifrequency
parallel data transmitter that accepts any of 100
possible characters from the business machine at
any rate up to 20 characters per second and transmits
these to data set 401J- or 403-type at the receiving
station.
1.04
Data is received at the interface from the
transmitting business machine in the form
2. PHYSICAL DESCRIPTION
2.01
Data set 401E-type is an integrated set
combining in one housing a telephone set,
the data transmitter, an electrical answer-back
amplifier, voice answer-back equipment (data sets
401El, 401E2, and 402E4), and remote testing.
circuits. Dimensions for data sets 401E2 and 401E3
and data sets 401E4 and 401E5 are shown in Fig. 1
and 2, respectively. Height of the data set with
handset in place is 4-1/2 inches.
2.02
Data set 401E-type is equipped with a 626A
key. This key is provided to facilitate testing
the data set on customer premises. The 626A key
is equipped with two pushbutton keys (TEST A
and TEST B). When depressed, either of these
ke~ causes a test signal to be transmitted to the
data test center for analysis. Some early production
sets were not equipped with this key and have no
provision for remote testing.
2.03
On the early production models of data set
401El, a Dl0M-61 cord is available for
connection to the telephone line, extension telephone,
and speakerphorie. The D4BJ-61 cord is furnished
with data set 401El. On data sets 401E2, 401E3,
401E4, and 401E5, the D6AA-61 cord is furnished.
When the D4BJ-61 cord or D6AA-61 cord is used,
connections are made on the 626A terminal strip.
@
American Telephone and Telegraph Company, 1973
Printed in U.S.A.
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