IBM 3274 User Manual page 59

3. Sends the message data.
4. Disconnects the host from the control unit and from the
telephone line by te.r:minating the telephone call.
To reduce operating time, an automatic answering feature,
called
Auto Answer,
can be added to the dial communication
equipment. This means that, when you dial the host system
telephone number, you need not speak to the host system
operator to establish the telephone connection; instead, you
listen for an answer tone. The telephone at your control unit
may also respond automatically to calls from the host system.
3274 dial-up telephone operation is possible if the 3274 has one
of the following features installed:
• Integrated Modem, Switched Line with Auto Answer
facility
• Integrated Modem, Switched Line without Auto Answer
facility (U.S. and Canada only)
• Integrated Modem, Nonswitched Line with Switched
Network Backup (SNBU) and Auto Answer facility
• Integrated Modem, Nq,nswitched Line with SNBU and
without Auto Answer facility (U.S. and Canada only)
• External Modem Interface (the modem attached to the 3274
should have switched network operation capability).
The SNBU capability is used only when the nonswitched line
(used for normal operation) has a transmission problem. When
there is a problem with the nons witched line, you may be
instructed by the appropriate person in your organization or by
your organization's operating procedures to use a switched line
(with SNBU) to continue operating.
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