INFICON XTC/3 Thin Film Deposition Controller Operating Manual - Manual (Page 75)

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XTC/3 Operating Manual
During deposition, XTC/3 will automatically switch to the next position with a good
crystal when there is a crystal failure. When the last good crystal fails, XTC/3 will
go directly to Time Power or STOP, as appropriate.
When configured for a Crystal12 sensor, the relay contacts are only pulsed closed
for one second then opened again once for each position. There is no
intermediate position.
3.6.8.4 Rotary Sensor Crystal Switching
Selecting Rotary sensor type enables sequential crystal switching only for six
positions. Upon a crystal switch, the Crystal Switch Output will close for one second
and then open (i.e., one pulse to move one position); there is no intermediate
position. XTC/3 will not keep track of which position the Rotary Sensor is on nor will
it keep track of which crystals are good and which are failed. All crystals are
assumed to be good following a START command. After the one-second pulse,
XTC/3 will attempt to find the resonant frequency for the crystal in this position.
If XTC/3 is in Deposit and does not find a good resonant frequency for this crystal,
it will again pulse the Crystal Switch Output for one second and attempt to find a
resonant frequency at this new position.
There will be a maximum of five attempts to find a good resonant frequency (i.e.,
a maximum of five pulses of the crystal switch output). If a good resonant frequency
is not found after five attempts, XTC/3 will then enter the Time Power, Idle-Ramp
or STOP state depending on whether Time Power in the Option sub-screen
of the Film Parameter display is set to Yes or No.
3.6.8.5 Dual Head
Only Sensor 1 may be configured as a Dual Head, (PN 750-212-G2 Dual Sensor
with second XIU). Sensor Shut 1 output must be wired so that it energizes the
Solenoid Valve which applies the air pressure to actuate the dual sensor shutter
mechanism, exposing crystal #2 (Sensor 2) while covering crystal #1 (Sensor 1).
Power-up initialization is performed to verify that the back-up crystal is good. If a
crystal fail occurs while in Deposit, the XTC/3 will switch to the backup crystal and
continue. There will not be an automatic crystal switch on failure from the backup
crystal #2 back to crystal #1 even if crystal #1 was not failed.
If START is attempted following completion of the layer and the next layer uses the
same sensor, the START will not be accepted (unless Start Without Backup is set
to Yes), and the message No Backup Crystal appears. The Crystal Fail state can
be cleared by pressing the TOGL key in the Sensors screen with the cursor on
Switch Crystal, by pressing the XTSW key from the Operate screen, via
communications command R14 (Crystal Switch) or by powering down and up
again and executing RESET or START. A good crystal must be available to switch
to in all cases. RateWatcher is not available with the Dual Head configuration but
the Transfer Sensor function is allowed.