IBM 3590 - Manual (Page 24)

The following lists the components of the operator panel:
1.
1 Unit Emergency Switch
v With the unit emergency power off (EPO) switch in the up position, it is
turned “on” and the AC power is applied to the entire subsystem.
v With the EPO switch in the down position, it is turned “off” and all
power is removed from the subsystem.
2.
2 System Power Switch
v In the upward position, a power on sequence will initiate.
v In the downward position, a power off sequence will initiate.
3.
3 Power On LED
v The green LED, labeled “Power On”, has three functions:
a. Off.
When off, power is removed from the 3590 drives and controller.
b. On.
When on, power is applied to the drives and controller. If the
Controller Status LED is off, the unit is ready for use.
c. Flashing.
As power is applied or removed, and the unit is not ready for use,
the LED will flash.
4.
4 Controller Status LED
v The yellow LED, labeled “Controller Status”, has the following
functions:
a. Off.
The controller detects no fault.
b. On.
The controller detects an, as of yet, uncorrected fault.
c. Flashing.
If a potential fault is detected in the controller, the LED will flash
while waiting for the controller to correct the fault. If, after a set
period of time, the controller does not verify the error, the LED
indicator will remain on in a continuous state. On means that the
LED is not flashing.
Note: There are two Controller Status LEDs on a 3590 A50 or dual controller
configuration. The upper-status LED represents CU 1, and the lower
status LED represents CU 0.
4 3590 Operator Guide