NAME
EmergencyPull Power On Power Off Interrupt
Wait
ManualSystem Test
Load
LoadUnit Load Prefix Select\) (I< Multisystem feature
EmergencyPull Switch IMPLEMENTATION Pull switch
Key, backlighted
Key
Key
Light
Light
Light
Light
Light
Three rotary switches
Key
Key switchPulling this switch turns off all power beyond the
power-entry terminal on every unit that is part of the
system or that can be switched onto the system. There
fore, the switch controls the system proper and all
off-line and shared control units and110 devices.
The switch latches in the out position and can be
restored to its in position by maintenance personnel
only.
When the emergency pull switch is in the out po
sition, the power-on key is ineffective.Power-On Key
This key is pressed to initiate the power-on sequence
of the system.
As part of the power-on sequence, a system reset is
performed in such a way that the system performs no
instructions or110 operations until explicitly directed.
the contents of main storage, including its protection
keys, remain preserved.
The power-on key is backlighted to indicate when
the power-on sequence is completed. The key is ef
fective only when the emergency pull switch is in its
in position.Power-Off Key
The power-off key is pressed to initiate the power-off
sequence of the system.
The contents of main storage and its protection keys
are preserved.
Interrupt Key
The interrupt key is pressed to request an external
interruption.
The interruption is taken when not masked off and
when theCPU is not stopped. Otherwise, the inter
ruption request remains pending. Bit 25 in the inter
ruption-code portion of the current psw is made one
to indicate that the interrupt key is the source of the
external interruption.
Wait Light
The wait light is on when theCPU is in the wait state. Manual Light
The manual light is on when theCPU is in the stopped
state. Several of the manual controls are effective only
when theCPU is stopped, that is, when the manual
light is on.System Light
The system light is on when theCPU cluster meter or
customer-engineering meter is running.
Programming Note
The states indicated by the wait and manual lights
are independent of each other; however, the state of
the system light is not independent of the state of
these two lights because of the definition of the run
ning condition for the meters. The following table
shows possible conditions.SYSTEM MANUAL WAIT CPU I/O LIGHT LIGHT LIGHT STATE STATE
off off off Not allowed when power is on
off off on Waiting Not operating
off on offStopped Not operating
off on on Stopped, Not operating
waiting
on off off Running Undetermined
on off on Waiting Operating
on on offStopped Operating
on on onStopped, Operating
waiting
Test Light
The test light is on when a manual control is not in
its normal position or when a maintenance function is
being performed forCPU, channels, or storage.
Any abnormal switch setting on the system control
panel or on any separate maintenance panel for theCPU, storage, or channels that can affect the normal
operation of a program causes the test light to be on.
The test light may be on when one or more diag
nostic functions under control ofDIAGNOSE are acti
vated or when certain abnormal circuit breaker or
thermal conditions occur.
The test light does not reflect the state of marginal
voltage controls.
Load Light
The load light is on during initial program loading;
it is turned on when the load key is pressed and is
turned off after the loading of the new psw is com
pleted successfully.
Load-Unit Switches
Three rotary switches provide the II-bit address of
the device to be used for initial program loading.System Control Panel 119
Emergency
Wait
Manual
Load
Load
Emergency
Key, backlighted
Key
Key
Light
Light
Light
Light
Light
Three rotary switches
Key
Key switch
power-entry terminal on every unit that is part of the
system or that can be switched onto the system. There
fore, the switch controls the system proper and all
off-line and shared control units and
The switch latches in the out position and can be
restored to its in position by maintenance personnel
only.
When the emergency pull switch is in the out po
sition, the power-on key is ineffective.
This key is pressed to initiate the power-on sequence
of the system.
As part of the power-on sequence, a system reset is
performed in such a way that the system performs no
instructions or
the contents of main storage, including its protection
keys, remain preserved.
The power-on key is backlighted to indicate when
the power-on sequence is completed. The key is ef
fective only when the emergency pull switch is in its
in position.
The power-off key is pressed to initiate the power-off
sequence of the system.
The contents of main storage and its protection keys
are preserved.
Interrupt Key
The interrupt key is pressed to request an external
interruption.
The interruption is taken when not masked off and
when the
ruption request remains pending. Bit 25 in the inter
ruption-code portion of the current psw is made one
to indicate that the interrupt key is the source of the
external interruption.
Wait Light
The wait light is on when the
The manual light is on when the
state. Several of the manual controls are effective only
when the
light is on.
The system light is on when the
customer-engineering meter is running.
Programming Note
The states indicated by the wait and manual lights
are independent of each other; however, the state of
the system light is not independent of the state of
these two lights because of the definition of the run
ning condition for the meters. The following table
shows possible conditions.
off off off Not allowed when power is on
off off on Waiting Not operating
off on off
off on on Stopped, Not operating
waiting
on off off Running Undetermined
on off on Waiting Operating
on on off
on on on
waiting
Test Light
The test light is on when a manual control is not in
its normal position or when a maintenance function is
being performed for
Any abnormal switch setting on the system control
panel or on any separate maintenance panel for the
operation of a program causes the test light to be on.
The test light may be on when one or more diag
nostic functions under control of
vated or when certain abnormal circuit breaker or
thermal conditions occur.
The test light does not reflect the state of marginal
voltage controls.
Load Light
The load light is on during initial program loading;
it is turned on when the load key is pressed and is
turned off after the loading of the new psw is com
pleted successfully.
Load-Unit Switches
Three rotary switches provide the II-bit address of
the device to be used for initial program loading.