INFICON MDC-260 Thin Film Deposition Controller - Manual (Page 72)

MDC-260 DEPOSITION CONTROLLER
PROGRAMMING AND CONTROLLER SETUP 4-36
Direct is used when the actuating device is driven directly. In this case the
controller creates one or two outputs, one for each available direction, to drive a
motor or solenoid.
4. Drive (Up, Down, Fast, Inline, Sngl Step, Dbl Step)
This parameter defines the drive method or direction for Direct control and only
has an effect when Control type is set to Direct. For that reason this parameter
will be hidden when the Control type is set to anything other than Direct. The
different drive settings are described below.
Up, Down, Fast and Inline - These four settings are typically used with multi-
crystal heads that use a motor to rotate the crystals into position. With Up
selected, the controller will create one output called "SensorN Drive Up". The
MDC-260 will activate this output to increment the sensor head up to the next
position. The down selection works the same except the output is called
"SensorN Drive Dn". With Fast selected, the controller will create both an up
and a down output. The 260 will then determine the fastest direction to the
target crystal position by activating the appropriate output. The Inline drive
type informs the controller that continuous travel in one direction is not
possible. Therefore to get from position 6 to 1, the direction must be down
through 5, 4, etc. until 1 is reached.
SnglStep and Dbl Step - Both the SnglStep and Dbl Step settings are typically
used with multi-crystal sensor heads that are actuated by pulsing a pneumatic
valve. The MDC-260 will create a "SensorX Drive Up" which is either singly
or doubly pulsed to sequentially step the sensor head to the next position.
5. Feedback Type (Individual, BCD, Single Home, In Position, No Feedback)
This parameter defines the type of feedback for a multiple sensor head. The three
feedback types available are as follows:
Individual - Individual position feedback. This feedback type uses one input
for each crystal position in the sensor head. All inputs are normally false
(open circuit) unless that crystal is in position then that input is true (closed to
ground). For example, a six crystal sensor head would use six inputs. If
crystal two was in position then all the inputs would be false except the input
connected to feedback position number two.
BCD - Binary Coded Decimal position feedback. This feedback type
uses binary coding to indicate which crystal is in position. Inputs are
numbered most significant bit first. For example, an eight crystal sensor head
would use three inputs. With crystal one in position, all inputs would be false.
With crystal four in position, inputs one and two would be true and input three
would be false.
Crystal
number Input
BCD2 Input
BCD1 Input
BCD0
1 OPEN OPEN OPEN
2 OPEN OPEN GND