Yokogawa YVP110 - Manual (Page 35)

<5. Setup>
5-2
IM 21B04C01-01E
(2) Selecting the Actuator Type
For the parameter VALVE_TYPE, set the value,
1 or 2, in accordance with the actuator type.
1 = linear-motion actuator
2 = rotary-motion actuator
Choosing the linear-motion type automatically
corrects a linearity error that is inherently
caused between the linearly acting actuator
and the rotating displacement sensor inside the
YVP110 actuator.
5.3 Carrying out Tuning
CAUTION
This function strokes the valve over its full range.
Do not execute while valve is controlling the
process. Keep away from the movable parts to
avoid injury.
After selecting the acting direction of the valve and
the actuator type, carry out auto tuning (and manual
tuning, if necessary). The auto tuning program
automatically:
• Adjusts the zero-point and span.
• Adjusts the parameter settings for controlling
the valve.
IMPORTANT
Auto Tuning in YVP110 sets the 0% point at the
position where the valve is fully closed and 100%
point at the position where the valve stem stops
against the mechanical stopper(fully open). If it is
necessary to adjust the zero point and span
precisely to the rated stroke of the valve, carry
out travel calibration which is described later in
this chapter after the Auto Tuning.
To carry out auto tuning, write a value to the
parameter AUTO_TUNE_EXEC according to the
following procedure.
CAUTION
For the first time after installing the YVP110
on the actuator or anytime after detaching the
YVP110 and installing it again on the actuator,
be sure to perform step (1) below, or (2) and
(3) to carry out all adjustments. Otherwise, the
adjustments cannot be carried out correctly.
From the next and any time thereafter, perform
only step (2) or (3) independently.
After detaching the YVP110 from the valve
actuator and then reinstalling it to the actuator,
be sure to perform step (2) below.
(1) To sequentially adjust the zero-point and span,
and then control parameter settings for the
first time after installing the YVP110 on a valve
actuator, write:
4 (= travel calibration at stop point and
control parameter tuning).
(2) To leave the control parameter settings
unchanged and only perform zero-point and
span adjustments such as after detaching the
YVP110 from the valve actuator and restoring it,
write:
2 (= travel calibration at stop point).
(3) To leave zero-point and span settings
unchanged and only adjust control parameter
settings, such as after the hysteresis of the
valve actions has greatly changed, write:
3 (= control parameter tuning).
The time needed to complete the adjustments,
which varies with the actuator size and the
hysteresis of the actions, is roughly 4 minutes
for a mid-capacity (capacity of around 3 liters)
actuator.
If you want to abort auto tuning for some reason
such as when you have started it while leaving
the air supply shut off, write:
5 (= cancel execution).