Flowserve Logix 520MD Plus Series User Instructions page 29

Table 16: Characteristic Curve Data
Command
Input
Linear
0.0 0.00
5.0 5.00
10.0 10.00
15.0 15.00
20.0 20.00
25.0 25.00
30.0 30.00
35.0 35.00
40.0 40.00
45.0 45.00
50.0 50.00
55.0 55.00
60.0 60.00
65.0 65.00
70.0 70.00
75.0 75.00
80.0 80.00
85.0 85.00
90.0 90.00
95.0 95.00
100.0 100.00
100
90
80
70
60
50
40
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100
Command Input
Figure 18: Characterization Curves
10.3.7 Configuration (Pressure Control)
►Configuration
►Pressure Control
►Window
The Configuration (Pressure Control) menu allows the user
to change the size of the pressure control window. This
window becomes active when the Valve Stability Switch is
set to "Hi". The Valve Stability Switch optimizes the
response for valves and actuators with high friction levels.
When set to "Hi", it slightly slows the response and will
normally stop limit cycling that can occur on high friction
valves.
© Flowserve Corporation
User Instructions - Logix® 520MD+ Series Digital Positioner
MaxFlo
MaxFlo =%
Linear
0.00 0.00
6.50 1.00
11.60 2.00
16.20 3.00
20.50 4.40
24.60 5.80
28.50 7.40
32.40 9.30
36.20 11.20
40.00 13.50
43.80 16.10
47.60 19.10
51.50 22.40
55.50 26.20
59.50 30.60
63.80 35.70
68.20 41.70
73.00 48.90
78.40 57.70
85.00 69.20
100.00 100.00
Linear
MaxFlo
Linear
MaxFlo =%
Valdisk
Linear
Valdisk =%
ShearStream
Linear
ShearStream
=%
Custom
Final Command
Valdisk
Valdisk =%
Linear
0.00 0.00
13.00 4.00
20.00 6.00
26.25 7.80
32.10 9.30
37.50 11.50
42.60 14.00
47.40 16.50
51.80 19.30
56.00 22.50
60.00 26.00
63.60 30.00
67.20 34.70
70.60 39.60
73.90 45.10
77.20 51.30
81.30 57.80
84.00 64.80
87.80 72.50
92.10 81.30
100.00 100.00
Window - When the position of the valve gets within the
pressure control window, the positioning algorithm will
change to pressure control. This means the pressures will
be held constant (locked), improving the stability of the
valve position.
10.3.8 Configuration (Soft Limits and Shutoff)
►Configuration
►Soft Limits & Shutoff
►High Soft Limit
►Low Soft Limit
►Upper Position Shutoff
►Lower Position Shutoff
Soft Limits allows the user to limit the movement of the
valve. Shutoff allows the user to tightly shut the valve with
all available force.
High Soft Limit and Low Soft Limit - This feature is used to
simulate physical blocks on the valve that restrict
movement past a set point. Once the Soft Limit is set, the
positioner will not attempt to move the valve position (final
command) beyond the set point, regardless of the analog
or digital command input signal.
CAUTION: Changing the Soft Limits may limit the
movement of the valve. The valve may not shut or open
fully.
NOTE: Removing power to below 3.6 mA will still cause
the valve to move to the de-energized state regardless of
the Soft Limits.
Upper Position Shutoff and Lower Position Shutoff - This
feature, (also called Minimum Position Cutoff or MPC) is
29
Field Trial Version – Printed October 28, 2011
FCD LGENIM0105-00
Shear-
Shear-
Stream
Stream =%
Linear
0.00 0.00
25.00 8.00
35.00 14.00
44.00 17.00
50.20 21.00
55.50 24.00
60.20 27.50
64.30 31.50
68.00 35.50
71.50 39.50
74.70 43.90
77.70 48.10
80.50 52.80
83.20 57.40
85.90 62.40
88.40 67.50
90.80 72.90
93.20 78.60
95.50 84.70
97.80 91.20
100.00 100.00
Custom
0.00
0.62
1.35
2.22
3.25
4.47
5.91
7.63
9.66
12.07
14.92
18.31
22.32
27.08
32.71
39.40
47.32
56.71
67.84
81.03
100.00