AT&T Bell System Plant Series Identification And Operation

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BELL SYSTEM PRACTICES
Plant Series
SECTION 594-015-100
Issue 1, January, 1963
AT&TCo Standard
DATA SET 401F
RECEIVER
IDENTIFICATION AND OPERATION
1. INTRODUCTION
1. 01 This section covers identification and
operation of data set 401F. It does
not include information for the business
machine associated with the data set.
2. GENERAL
2.01 Data set 40 lF is primarily designed
for use in DATA-PHONE service.
It can also be arranged for use on local
battery 2-wire private lines.
2. 02 Data received from the telephone
line consists of three tones. Each
tone may be one of several frequencies.
The data set converts these tones into
contact closures. These closures are de-
livered to the associated business machine
as received data.
2. 03 The data set is used with a 513B-61
telephone set equipped with a DlON-61
cord (Fig. 1). The DATA key is lo-
--- cated on the switchhook assembly in the
same position as an exclusion key and
operates in the same manner. A TEST
key permits a general test of the data set
from a data test center. TEST lamp lights
when data set is in test mode.
3. DESCRIPTION
3. 01 Data set 401F is composed of several
major components enclosed in a
two-tone gray cabinet. These components
are:
• Control Circuit
• Channel Circuits
• Power Supply
• Cut-Apart Filter
• Automatic-Answer Circuit
• Data Output Relays
• Te st- Circuit.
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
spring relays are used for automatic-
answer and control circuits. The control
circuit also uses one dry reed relay mounted
in combination with the data output relays
and several individual dry reed relays
mounted on a printed board assembly.
Fig. 3 shows arrangement of components
in the cabinet.
3. 04 Fig. 4 shows a simplified block dia-
gram of the data set.
3. 05 Frequencies accepted by data &et
40 lF are shown in Table A. Minimum
receiving level for each tone should be no
lower than -39 dbm for frequencies below
1950 cps and -49 dbm for frequencies of
1950 cps and above.
3. 06 The answer-back oscillator responds
to signals from the business machine
and transmits tones back to the distant
station. Frequencies of the tones are
1017 and 1785 cps.
3. 07 A D3BT-61 cord, -5-1/2 feet long,
equipped with a Cannon MC-14E-8-3SN
plug on one end is furnished for connections
between the TEL LINE jack on the data set
and the telephone line.
3. 08 A KS-14532, List 15 gray cord assem-
bly, 10 feet long, is provided for con-
nection to a 117-volt ac power receptacle
(two parallel blades and a u-·shaped ground-
ing pin).
©
American Telephone and Telegraph Company, 1963
Printed in U.S. A.
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