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XTC/3 Operating Manual
3.5.1 Alarms and Stops
There are a number of unusual XTC/3 situations that may require operator
attention. These situations are detected and then treated as
ALARMS
or
STOPS
.
Both
ALARM
s and
STOP
s can be indicated by a separate relay closure (by default
or selected assignment in XTC/3M, by fixed assignment in XTC/3S).
An
ALARM
condition is not fatal, XTC/3 will continue the layer or process
to normal termination.
A
STOP
is fatal, immediately halting the process. If desired, the user may set the
STOP ON ALARM
parameter in the
Process
sub-screen of the
General
Parameter
display to configure XTC/3 to treat an
ALARM
the same as
STOP
(i.e., halt processing upon detection of the abnormal condition).
3.5.1.1 Alarms
The following conditions are considered
ALARM
s by XTC/3 and result in the
closure of the
ALARM
relay (if assigned):
Crucible hearth selection is not validated by the
CRUC VALID
input
within thirty seconds.
Rate control not established during the first sixty seconds of
SHUTTER DELAY
(or twenty times the
TIME CONSTANT
if greater).
Rate has been out of control in
DEPOSIT
for sixty seconds (or twenty times the
TIME CONSTANT
if greater). Out of control is defined as a rate error >0.5 Å/s
and >5% of setpoint deposit rate.
The source power has exceeded the
Maximum Power
parameter, set in the
Source sub-screen of the Film Parameter display, for five continuous seconds.
3.5.1.2 Stops
The following actions or conditions produce a
STOP
state. This condition is
indicated by the
STOP
message on XTC/3 and the closure of the
STOP
relay
(if assigned):
An intentional or accidental interruption of power, indicated by
the
Power Loss
message.
A
Switcher Fail
message appears as the result of a failure to detect a valid
position in a multi-position sensor.
Pressing the front panel
STOP
key on XTC/3 or handheld controller.
Initiating a
STOP
via remote communication.
Activating the
STOP
external input.
A
CRYSTAL FAIL
detected during any pre-deposit phase (when crystal
switching is not available).