Installation Manual

Theory of Operation 7-7
Positional Sensors
XY Linear Encoders
The X Linear Encoder is located on top of the X-beam and the Y Linear Encoder is located under the
left Y-rail. These encoders supply Dispensing Head XY positional information on a constant basis to
the PMAC.
Rotary Encoder
Each Servo Motor has its own Rotary Encoder. These encoders supply X, Y, and Z Servo Motor velocity
and acceleration information to the PMAC.
Hall Sensor
Each Servo Motor has its own Hall Sensor. These sensors Monitor the direction of rotation for the X, Y,
and Z Servo Motors and report angular position signals to the Servo Amplifier.
Dispensing Head
Dispense Head Controller
As with the Conveyor Controller, the heart of the Dispense Head Controller is the Microcontroller. The
Controller receives commands from software through the CAN bus for direct I/O control and changes of
system configuration. CAN is also used for updating software with the status of the Dispense Head
Controller operations. Although the software can have direct control over Dispensing Head operations,
the majority of the time the Dispense Head Controller acts independently to manage all local processes
and I/O. These processes include:
Dispensing Valve Speed and Acceleration Control
Control of Camera Lighting
Control of Needle Heaters
Control Pneumatic Solenoids
Z Servo Interface PWA
The PMAC motor signals for the Z-axis are amplified by the Z Servo Amplifier which is built into the
Z Servo Interface PWA located inside the Dispensing Head.
Head Mechanics
The Dispensing Head has a counter balanced, rack and pinion drive that is powered by a Servo Motor
Assembly. The motor is located in the Dispensing Head and has both Hall and Rotary Encoders.