Control Panel; Power-On Switches And Lights - IBM 7074 General Information Manual

Control Panel
The control panel of the 7631 is primarily intended
for maintenance simulation purposes. The panel is
mounted on the right front cover. The control panel
has an exposed section and a hidden section, intended
only for customer engineering usage. On the exposed
segment there are 122 indicator lights which reHect
the status of data and controls within the 7631. Oper-
ator switches are available in a light and switch as-
sembly above the indicator section of the control
panel. The customer engineer section of the panel is
covered and contains 35 switches for simulation of
data, commands and responses from the channel, and
responses from the files.
Power-On Switches and Lights
Power-On Key supplies
DC
voltages to the 7631 and
the 1301's and
AC
voltages to the disk storage motors
and blowers. When the switch is pressed, power is sup-
plied to the first disk storage for a power-on sequence.
When the first disk storage has completed its power-
on sequencing, a signal is sent to the next one to start
the power-on sequence, and so on.
Power-On Light, when on, indicates that power is
supplied to the 7631 and the 1301's.
20
Power-Off Key removes
DC
and
AC
operating voltages
from the 7631 and the 1301's and initiates a power-off
sequence for the 1301's.
DC-Off Key removes
DC
operating voltages from the
7631 and the 1301's.
DC-On Light, when on, indicates that
DC
operating
voltages are present on the 7631 and the 1301's.
HAO Switch: This switch must be on for logical
execution of, a home address operation.
Write Inhibit Switch and Light: The write inhibit
toggle switch allows the
CE
or diagnostic programmer
to perform a write sequence of operations without
the actual writing, thus not disturbing the customer's
data. The associated light indicates this write inhibit
condition present.
Thermal Light: This light is energized in the 7631
if the temperature in the gates exceeds 115 0 F. While
the light is on, the power-on switch of the 7631 is not
effective. Power is down until the temperature returns
to specified limits.
Fuse Light: The fuse light indicates a blown fuse
or tripped cricuit breaker in the 7631.
Test Mode Light: For customer engineering use.
When this light is on, it indicates that the 7631 and
the attached 1301's are not available for normal cus-
tomer use.