Yokogawa YVP110 - Manual (Page 151)

<Appendix 6. Manual Tuning Guideline>
A-40
IM 21B04C01-01E
• If necessary, increment the value for SERVO_
RESET by 5.
• The same boost value is set on both the air
delivery and exhaust sides by Auto Tuning. If
the overshoot on the exhaust side is larger than
that on the air delivery side for a double-acting
model, input a negative value in X_BOOST_
VALUE [1] [2], without changing the value of
0 in X_BST_ON_THRESHOLD [1] [2] and
X_BST_OFF_THRESHOLD [1] [2]. First, try to
input a negative value of half that of BOOST_
VALUE [1] [2], and if necessary, increment or
decrement the value by 1.
(3) Improving the stabilization time and slow
overshoot
Decrease the value for SERVO_RESET to improve
the capability of tracking the target value. However,
if the value is too small, the hunting operation or
limit cycle may occur. Verify the 10% step response
and decrement the value by 2 to 3.
(4) Improving the response time
• Increment or decrement the value for BOOST_
VALUE [1] [2] and X_BOOST_VALUE [1] [2] by
2, respectively.
• If necessary, increment the value for SERVO_
GAIN by 30.
(5) Checking hunting operation
Input a value in a large step of approx. 80% to
ensure the hunting operation does not occur. If the
hunting operaion does occur, decrease the value for
SERVO_GAIN to 2/3 or 1/2 of the originally entered
value. Then, increase the value for SERVO_
RESET by approx. 1.5 times.
(6) After tuning the control parameters,
re-check each parameter if necessary.
A6.3 Examples of Tuning Control Parameters
The following table shows examples of tuning parameters for double-acting actuators.
[1] Valtek25sq.in. double-acting actuator, stroke = 0.75 in, capacity = approx. 300 cc,
supply pressure = 400 kPa, hysteresis = 150N
[2] Valtek25sq.in. double-acting actuator, stroke = 0.75 in, capacity = approx. 300 cc,
supply pressure = 400 kPa, hysteresis = 380N
[3] Valtek50sq.in. double-acting actuator, stroke = 2.5 in, capacity = approx. 2000 cc,
supply pressure = 400 kPa, hysteresis = 300N
[4] Valtek50sq.in. double-acting actuator, stroke = 2.5 in, capacity = approx. 2000 cc,
supply pressure = 400 kPa, hysteresis = 1200N
Parameter Name
(Figures in parentheses represent default
values (factory settings))
Valtek25sq.in. Stroke = 0.75 in. Valtek50sq.in. Stroke = 2.5 in.
Hysteresis =
150N
Hysteresis =
380N
Hysteresis =
300N
Hysteresis =
1200N
SERVO_GAIN (120) 140 120 350 300
SERVO_RESET (15) 8 8 9 24
SERVO_RATE (0.22) 0.4 0.4 0.6 0.5
SERVO_RATE_GAIN (5.0) 10.0 10.0 5.0 5.0
SERVO_DEADBAND (0.0) 0.0 0.0 0.0 0.0
SERVO_OFFSET (55.0) (55.0) Default (55.0) Default (55.0) Default (55.0) Default
BOOST_ON_THRESHOLD[1][2] (1.9, 2.9) 0.9, 1.9 0.9, 1.9 0.9, 5.1 0.9, 1.9
BOOST_OFF_THRESHOLD[1][2] (1.0, 1.0) 0.5, 0.5 0.5, 0.5 0.5, 0.5 0.5, 0.5
BOOST_VALUE[1][2] (8.0, 10.0) 8.0, 10.0 8.0, 10.0 6.0, 10.0 6.0, 8.0
SERVO_I_SLEEP_LMT (0.0) 1.4 1.4 1.8 1.7
SERVO_P_ALPHA (0.0) 0.0 0.0 0.0 0.0
INTERNAL_GAIN (5.0) 6.8 6.8 14.1 14.1
X_BST_ON_THRESHOLD[1][2] (0.0, 0.0) 0.0, 0.0 0.0, 0.0 0.0, 0.0 0.0, 0.0
X_BST_OFF_THRESHOLD[1][2](0.0, 0.0) 0.0, 0.0 0.0, 0.0 0.0, 0.0 0.0, 0.0
X_BOOST_VALUE[1][2] (0.0, 0.0) -4.0, -5.0 -8.0, -10.0 -3.0, -6.0 -3.0, -4.0
The above adjusted values are only for reference. Adjust parameters depending on the individual valve, actuator, and operating conditions.
X_BST_ON_THRESHOLD, X_BST_OFF_THRESHOLD, and X_BOOST_VALUE are parameters that are only valid for double-acting
models.