AT&T Bell System Plant Series Identification And Operation

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BELL SYSTEM PRACTICES
Plant Series
SECTION 594-011-100
Is sue 5, January, 1963
AT&:TCo Standard
DATA SETS 401B, D
RECEIVERS
IDENTIFICATION AND OPERATION
1. INTRODUCTION
1. 01 This section covers identification and
operation of data sets 401B and 401D.
It does not include information for the busi-
ness machine associated with the data set.
1. 02 This section is reissued to:
• Delete installation, connection,
maintenance, and test information
for data sets 401B and 401D.
• Delete all information cone erning
data set 401F.
1. 03 Information formerly covered in
Section 594-011-100, Issue 4 will be
covered as shown in Table A.
TABLE A
DATA SET INFORMATION
Data
Set Material Covered
Section
Installation and
594-011-200
Connections
401B, D
Maintenance 594-011-300
Test Procedures
594-011-500
Description and
594-015-100
Operation
401F
Installation and
594-015-200
Connections
Maintenance
594-015-300
Test Procedures 594-015-500
1. 04 Due to extensive changes marginal
arrows have been omitted.
2. GENERAL
2.01 Data sets 401B and 401D are pri-
marily designed for use in DATA-
PHONE service on central office or PBX
station lines. They also can be arranged for
use on 2-wire private lines (local battery).
2. 02 Data received from the telephone line
consists of either two tones (data set
401B) or three tones (data set 401D). Each
tone may be one of several frequencies.
The data set converts these tones into con-
tact closures. These closures are delivered
to the associated business machine as re-
ceived data.
2. 03 The data set is used with a 502BR-6I
telephone set equipped with a
D6AC-6 l cord and modified to permit con-
trol of the data set (Fig. 1). The DATA
key is located on the switchhook assembly
in the same position as an exclusion key
and operates in the same manner.
2. 04 When used on a private line the data
set is always in data mode and the
telephone set is not required.
3. DESCRIPTION
3. 01 The data set is composed of several
major components enclosed in a two-
tone gray cabinet. Components are listed
below:
• Control Circuit
• Channel Circuits
• Power Supply
• Cut-Apart Filter
• Automatic Answer Circuit
• Data Output Relays
3. 02 Electronic circuits are arranged on
plug-in printed board assemblies.
Fig. 2 shows a typical assembly.
3. 03 Dry reed relays are used for data
output to the business machine. Wire
©
American Telephone and Telegraph Company, 1963
Printed in U. S. A.
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