Dynaflow, User manual - operation – Ransburg DynaFlow User Manual User Manual

Page 40

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LN-9400-00.9

DynaFlow

TM

User Manual - Operation

36

Deadband would be between 95 and 105 cc/min.

The PID controller would therefore be suspended

whenever the actual flow rate is within this range.

This parameter should normally be set to 1 cc/min.

Proportional Gain (Kp) (Master and

Slave)

The proportional PID controller gain mainly affects

the response of the DynaFlow system to distur-

bances. The DynaFlow system may operate with

Kp at zero, however response to material supply

and delivery pressure disturbances will be poor.

The value of Kp is divided internally by a factor

of 1,000 and is used as a multiplier for the flow

rate error term. The flow rate error term is the

difference between the set point and actual flow

rate for the CHANNEL.

Integral Gain (Ki) (Master and Slave)

The integral PID controller gain mainly affects the

steady-state (non-transitional) response of the

DynaFlow system. The DynaFlow system must

have a non-zero value for Ki to operate properly.

The valve of Ki is divided internally by a factor of

100,000 and is used as a multiplier, along with a

factor of 3, for the sum of the error term over the

time the trigger has been turned on.

Derivative Gain (Kd) (Master and Slave)

The differential PID controller gain mainly affects

the response of the DynaFlow system to distur-

bances caused by disturbances that are slow in

nature. Normally, the DynaFlow system may op-

erate with a Kd value of zero. The value of Kd is

divided internally by a factor of 1,000 and is used

as a multiplier, along with a factor of 1/3, for the

rate of change in the error term.

MVR Low Pressure (Master and Slave)

This parameter allows the operator to set the low

limit on the pressure sent to the fluid regulator

while in the Run or Load modes. It can be used

to cause a faster response by the transducer/

regulator system. It should be adjusted so that

the regulator valve is just short of opening. With

a standard MVR valve, this value should never

exceed 30 psi. If this value is too high, continuous

FLOW TOO HIGH faults will occur.

When a GUN is configured for two-component

operation and the Ratio is 99.0:1, or greater, the

GUN is said to be operating in pseudo single-

component mode. In this case, the slave (catalyst)

CHANNEL is NOT set to MVR LOW when the GUN

is placed in either Run or Load modes. However,

if the slave (catalyst) CHANNEL is specified as

a clean CHANNEL, it will be turned on to MVR

HIGH in Clean mode.

MVR High and MVR Low Effect On PID

Operation

The PID will only output transducer pressures

between MVR LOW and MVR HIGH.

Pulses/Liter (Master and Slave)

The number of pulses sent from the flow meter to

the controller for each unit of fluid flow. Each pulse

represents a volume of fluid and is dependent

on flow meter size. This value can be verified or

adjusted during a calibration process to achieve

the best accuracy (See "Calibration Mode" in

the "Operation" section of this manual). The cali-

bration of all flow meters should be periodically

checked. The rheology of some fluids may effect

the calibration values, therefore a different value

for pulses per liter may be used for each material

and is entered into the JOB data tables.

Deadband (Master and Slave)

This represents a flow rate range divided equally

above and below the set point flow rate in which the

PID controll is suspended. This keeps the control

output from continually changing and produces

stability when close to the requested value. For

example, if the Deadband is set for 5 cc/min and

flow rate set point is set for 100 cc/min, the

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