3274 Dial-Up Telephone Facilities; Dialoperation - IBM 3274 User Manual

3274 Dial-Up Telephone Facilities
Dial Operation
The 3274 Model 5IC and 6IC cluster (3274 and its attached
display stations and printers) is connected to its host system by
telephone lines. Telephone equipment can be attached to your
3274 that allows you to communicate with the host system by
dialing the host system's telephone number. The host system
can also communicate with your cluster by dialing the
telephone attached to the 3274. With the dial equipment
installed, the telephone lines can be used for transmission of
data processing information and, at other times, for normal
telephone conversations.
Either the control unit or the host system can initiate a
telephone dial-up operation. The operator performs the
following main steps when sending information to the host
system by the dial method:
1. Dials the host system telephone number and establishes a
telephone line connection.
2.
Performs the logon procedure when directed by the host
system operator.
3.
Enters the message data and sends it to the host system.
4.
Disconnects the control unit from the host system and from
the telephone line by terminating the telephone call.
When the host system initiates a telephone dial-up operation,
it:
1.
Dials the control unit telephone number.
2. Asks for control unit operator identification.
Section
1.
Operator Information
1-47