User`s manual

82 Chapter 7 535 User's Manual
Applications
NOTE: Adaptive tuning is not available
with velocity position proportioning
control.
e. If the valve oscillates, increase the P.PROP.D.B. value by 0.5%; re-
peat until oscillation stops.
12. Set the parameter S/W BREAK to define the output value for when the slide-
wire breaks.
E. VELOCITY POSITION PROPORTIONING CONTROL
Velocity position proportioning does not utilize direct feedback. It estimates
the position of the actuator, based on time and the speed of the actuator.
In automatic control mode, the controller will display “CW” to refer to energizing
of the clockwise relay, and “CCW” to refer to energizing of the counterclockwise
relay. A blank display means that both relays are de-energized.
In manual control mode, the display is blank unless an output change is being
made. Use the
▲▲
▲▲
▲ and
▼▼
▼▼
▼ keys to change the output; the relay is only energized
while the keys are being pressed. The display indicates the percentage change
in valve position in real time. The rate of change is dependent on the values
entered for CCW TIME and CW TIME.
The controller will transfer to manual control due to a lost process variable (PV.
BREAK), a digital input closure (DES.OUTPT.), a power-up sequence
(PWR.UP:OUT.), or lost communications (SHED OUT). In these cases, the
output can be set to: remain at its last value with both relays de-energized (OUTS
OFF); rotate fully counterclockwise (CCW); or rotate fully clockwise (CW). CCW
and CW will energize the respective relay for a period two times that of the CCW
TIME or CW TIME.
Hardware Configuration
• The controller must have mechanical relay, solid state relay or DC logic
modules installed in the first two output sockets.
Refer to the section on Chapter 1 for more information.
Software Configuration
1. Go to CONFIG. menu.
Set CTRL. TYPE to POS. PROP.
2. Go to the CONTROL menu.
Set P.P. TYPE to VELOCITY.
3. Set CCW TIME to the amount of time (in seconds) it takes for the actuator
to fully rotate in the counterclockwise direction.
Set CW TIME to the amount of time (in seconds) it takes for the actuator to
fully rotate in the clockwise direction.
Loads on the valve may affect the time required, therefore, it is best to measure
these values when the valve is in service. As an alternative, enter the values
specified by the actuator manufacturer and then make adjustments later.
5. Set MIN. TIME to the minimum amount of time the controller must specify
for the motor to be on before it takes any action.
6. Set values for PV. BREAK, DES. OUTPT., PWR.UP:OUT. and SHED OUT.