Logix 3400MD Digital Positioner FCD LGENIM3404-00 – 9/09
16
Table VI : Characteristic Curve Data
% Command
% Control Command
=%
Linear
Custom
QO
0
0
0
0
0
5
0.62
5
8.66
18.8
10
1.35
10
16.24
37.6
15
2.22
15
23.17
56.4
20
3.25
20
30.11
74.0
25
4.47
25
35.31
84.3
30
5.91
30
40.51
90.0
35
7.63
35
45.42
92.0
40
9.66
40
50.34
93.4
45
12.07
45
54.40
94.2
50
14.92
50
58.47
94.8
55
18.31
55
62.39
95.5
60
22.32
60
66.31
96.0
65
27.08
65
70.27
96.5
70
32.71
70
74.23
97.0
75
39.40
75
78.17
97.5
80
47.32
80
82.11
98.0
85
56.71
85
85.50
98.5
90
67.84
90
88.89
99.0
95
81.03
95
94.45
99.5
100
100.00
100
100.00
100.0
Auto Tune
This switch controls whether the positioner will auto tune itself every
time the RE-CAL button is pressed or use preset tuning parameters.
On
On
enables an auto tune feature that will automatically determine
the positioner gain settings based on the current position of the adjust-
able GAIN switch setting and response parameters measured during
the last RE-CAL. The GAIN switch is live, meaning the settings can be
adjusted at any time by changing the rotary switch position. (Note that
there is a small black arrow indicating the selection. The slot in the
switch is NOT the indicator.)
Figure 10: Adjustable GAIN Switch
A
GAIN
B
C
D
E
F
G
H
If the adjustable GAIN selector switch is set to “E” with the auto tune
switch on, a Flowserve standard response tuning set will be calculated
and used based on response parameters measured during the last
RE-CAL.
If the adjustable GAIN selector switch is set to “D”, “C”, “B”, or “A” with
the auto tune switch on, progressively lower gain settings will be used
based on response parameters measured during the last RE-CAL.
If the adjustable GAIN selector switch is set to “F”, “G”, or “H” with
the auto tune switch on, progressively higher gain settings will be
calculated and used based on response parameters measured during
the last RE-CAL.
Off
Off
forces the positioner to use one of the factory preset
tuning sets determined by the adjustable GAIN selector switch.
Settings “A” through “H” are progressively higher gain predefined
tuning sets. The GAIN selector switch is live and can be adjusted at
any time to modify the tuning parameters.
NOTE:
“E” is the default adjustable GAIN selector switch setting for
all actuator sizes. Raising or lowering the gain setting is a function
of the positioner/valve response to the control signal, and is not
actuator size dependent.
Stability Switch
This switch adjusts the position control algorithm of the positioner for
use with low-friction control valves or high-friction automated valves.
Low-Friction Valves
Placing the switch to the left optimizes the
response for low-friction, high-performance control valves. This setting
provides for optimum response times when used with most low-friction
control valves.
High-Friction Valves
Placing the switch to the right optimizes
the response for valves and actuators with high friction levels. This
setting slightly slows the response and will normally stop limit
cycling that can occur on high-friction valves.
7.4 Description of Cal DIP Switch Settings
The sixth DIP switch selects between two calibration options. The
function of the Cal DIP switch is described below.
NOTE:
The unit must be in OOS mode before a calibration sequence can
begin.
Auto
Select
Auto
if the valve/actuator assembly has an internal stop
in the open position. In
Auto
mode the positioner will fully
close
the
valve and register the 0% position and then
open
the valve to the stop
to register the 100% position when performing a self-calibration. See
detailed instructions in the next section on how to perform an auto
positioner calibration.
Jog
Select
Jog
if the valve/actuator assembly has no physical
calibration stop in the open position. In the
Jog
mode the positioner will
fully close the valve for the 0% position and then wait for the user to set
the open position using the Jog buttons labeled with the up and down
