DIGISPENSE 3020 CONTROLLER MODULE
Page 3-7
7 April, 2011
IVEK Corp.
P03L011B
The movement of the piston is either forward (dispense) or reverse (load). A dispense is typically a settable volume of
fluid movement while a load is an attempt to prepare the chamber for the next dispense (dependent on mode of
operation). A dispense, depending on mode, allows for configurations based on rate, drawback, volume, etc. A load
can only be configured for rate.
Fluid movement is controllable from two different contexts: Production Mode and Fluidic Setup Mode. Production
Mode is intended for normal controlled fluidic movement operations and Fluidic Setup Modes are intended for
preparing the entire fluidic system for those controlled operations.
3.1.4 Dispense/Load Rate
The optimum value of the Dispense or Load Rate needs to balance decreasing cycle times with an increasing risk of
cavitations of the fluid reducing repeatability. Also, since motor torque decreases with increasing speeds, the
probability of stalling the motor in the Actuator Module increases, especially when the viscosity of the fluid is high.
Often, a larger diameter tubing is used between the supply reservoir and the pump so the chamber may be prepared
for the dispense more quickly. This often allows for the use of a much faster load rate to reduce the overall cycle time
of the operation.
Since a precisely controlled dispense is often the goal of the system, the fluidic system attached to the active port is
often carefully selected based on desired volume, fluidic characteristics, etc. This means the dispense rate is often
lower than the load rate to increase repeatability and reduce the probability of fluid cavitations.
Advantages
Disadvantages
Decreased Rates
Lower probability of stalls & fluid cavitations
Longer cycle time
Increased Rates
Shorter cycle time
Higher probability of stalls & fluid cavitations
3.1.5 Direction
In some modes of operation (all Production Modes and Prime Mode), a direction selection of either forward or reverse
is available. This selection determines the direction of fluid movement through the Pump Module.
When the direction is forward, fluid moves into the inactive port (Intake) and out the active port (Discharge). When the
direction is reverse, fluid moves into the active port and out of the inactive port.
3.1.6 Active Port
The Pump Module contains two ports, Port A and Port B, for connection to the fluidic system. One port is always
designated as the active port and the active port is always the discharge port. It is only necessary to change the active
port if doing so eases the location of the tubing and other elements of the fluidic system.
Active port configuration is provided in the Setup C screen to allow initial fluidic system setup/location. Changing the
active port in effect reverses the fluidic movement direction, the controlled Dispense portion of the operation will now
occur at the opposite port location with the opposite rates. Following is a chart illustrating the nature of fluidic
movement based on active port selection and direction.
Active Port - Port B (Default)
Direction
Port A
Port B
Forward
Inlet
Outlet
Reverse
Outlet
Inlet
Active Port – Port A
Direction
Port A
Port B
Forward
Outlet
Inlet
Reverse
Inlet
Outlet
