IBM 3274 51C Maintenance Information page 184

Ref
D
fJ
D
II
Alt IML
Address
Model51C
LJL_~---:::::~ Only
Description
On/Off switch:
In
=
On;
l.QJ
=
Off.
On indicator: Indicates the 3274 is on.
IML (Initial Machine Load) pushbutton: Pressing
and holding causes a basic test to run. When the
pushbutton is released, IML tests start. At com-
pletion, the machine is loaded.
Alt IML Address switch:
• 1: Holding, while pressing the IML pushbutton,
bypasses the tests and loads the machine
directly. Use only after normal IML fails.
• 2: Holding, while pressing the IML pushbutton,
invokes adapter and wrap tests.
8 4 2 1 indicators: These light while the IML push-
button is held. During IML. they follow the test
sequence. At completion, they all go out. During
operation, they indicate operational status.
Call In Progress Indicator: Indicates that a connection
has been established (switched network only).
Ref
o
m
Figure D-4. 3274 Operator Panel - Models 51C/52C with 1200-bps Integrated
Modem with
(1)
Switched Line with Auto Answer Feature or (2)
NQnswitched Line with Auto Answer Feature
D-6
Description
Talk/Data Switch
• Talk Position - The operator may use the handset
for voice communication.
• Data Position - The handset is bypassed; only
machine data is allowed on the communication
line (switched network only).
Primary/Secondary Speed Switch - In the Primary
position the modem operates at normal speed;
in the Secondary position the modem operates
at half speed.
Transmit Level Attenuation Switches (switched net-
work/U.S. and Canada only) - These four switches
provide 0 to -15 dB attenuation of the transmit
level in 1 dB increments.
Encrypt/Decrypt Key Switch - Allows a new master
key to be entered when in the horizontal position.
Encrypt/Decrypt Battery - Allows the master key to
be maintained in the 3274 when power is off.