Teletype 38 Description And Operation

TELETYPE CORPORATION
Skokie, Illinois, U .S .A.
SECTION 574-423-l0OTC
Issue 2, June 1973
88 ELECTRICAL SER VICE UNITS
DESCRIPTION AND OPERATION
1.
2.
CONTENTS
GENERAL ..... .
ELECTRICAL SERVICE UNIT
PROVIDING DC AND EIA
INTERFACE (WESU00l)
DESCRIPTION . . . .
TECHNICAL DATA
A. Signal and Control
Interface .....
B. Physical, Electrical, and
Environmental
Characteristics
OPERATION ...
3. ELECTRICAL SERVICE UNIT
PROVIDING FSK (FREQUENCY
SHIFTED KEYlNG) INTERFACE
PAGE
1
1
1
2
2
3
3
(WESU002) . . . 10
DESCRIPTION . . . .
TECHNICAL DATA
A.
B.
C.
D.
Interface ......... .
Carrier Frequencies
Signal Level .....
Physical, Electrical, and
Environmental
Characteristics
OPERATION ...
A. Modem Card ( 322490)
1216SD ...... .
B. Logic Card (322491)
1227SD ....... .
1. GENERAL
10
10
10
10
10
10
10
11
11
1.01 This section provides the description
and operation of the 38 electrical
service units. It is reissued to make some addi- .-
tions and minor corrections; Marginal arrows .,._
indicate the changes and additions.
If
a detailed ._
circuit description is required, refer to the appro-
priate WDP (Wiring Diagram Package).
1.02 Two types of electrical service units are
covered in this section. The first unit to
be covered (WESU00l) provides both de
(current/no current), and EIA (Electronics Indus-
tries Association) Standard RS-232-C interfacing.
The second unit to be covered (WESU002) uses
FSK (Frequency Shifted Keying) to provide
interfacing with a private telephone line or some
data access arrangement. Both units can be
mounted in the pedestal of the floor model or in
a separate housing for the table model.
2. ELECTRICAL SERVICE UNIT PRO-
VIDING DC AND EIA INTERFACE
(WESU00l)
DESCRIPTION
2.01 The physical make-up of the electrical
service unit consists of a main baseplate
on which is mounted a de power supply and a
circuit card assembly. Mounting facilities are also
provided for various options such as a reader
power pack or an elapsed timer.
2.02 A six-pushbutton cluster with internal
indicator lamps, that is connected by
cable to the electrical service unit, provides the
operator with mode switching, break generation,
and manual answer-back trip, and also a visual
indication of the mode status or alarm condition.
Two cables are supplied with the electrical service
unit; one goes to the connector board at the rear
of the printer, the other goes to the motor.
2.03 A connector assembly with spare termi-
nals is provided for customer con-
nection of de signal lines. When EIA interface is
used, the customer can provide his own connector
or use an optional interface cable available from
Teletype Corporation. There is an auxiliary con-
nector on the circuit card that provides custon>:r
access to the "EOT" (End of Transmission) and
"paper-out" contacts. The connector also pro-
vides for remote switching of the "answer-back"
mechanism.
©
1972 by Teletype Corporation
All rights reserved
Printed in U.S.A.
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