Badger Meter SRD/SRI Valve Positioners - Manual (Page 47)

Table 4: Allocation of the parameter values to coding:
In LCD shown values: [in Menu Nr.]
Code
LEDs
1 2 3 4
P [6.1]
P [6.2]
Tn [6.3]
Tn [6.4]
(sec)
T63 [6.5]
T63 [6.6]
(sec)
Dead band
[6.7]
(%)
1 1 0 0 0 2 1 0.1 0
2 0 1 0 0 2.66 1.33 0.15 0.12
3 1 1 0 0 3.50 1.75 0.25 0.16
4 0 0 1 0 4.7 2.4 0.35 0.22
5 1 0 1 0 6.3 3.2 0.5 0.3
6 0 1 1 0 8.4 4.2 0.75 0.4
7 1 1 1 0 11.2 5.6 1.15 0.53
8 0 0 0 1 15 7.5 1.75 0.7
9 1 0 0 1 20 10 2.6 0.94
10 0 1 0 1 26.6 13.3 3.9 1.25
11 1 1 0 1 35.5 17.8 5.9 1.67
12 0 0 1 1 47.3 23.7 8.85 2.22
13 1 0 1 1 63.1 31.6 13.3 2.96
14 0 1 1 1 84.2 42.1 20 3.95
15 1 1 1 1 112.2 - off - 30 5.3
Allocation of the parameter values to coding
Remarks to Controller Tuning
If AUTOSTART does not find the optimum setting the
following may be the result:
• A) small response to setpoint, long positioning time or
long neutral time
• B) continuous oscillation following setpoint jump
• C) wide and high overshoot
For the assessment of the control 12 5% jumps in both
directions may be performed in Menu 8 The valve dynamics
may be observed at LCD or the mechanical indicator
Prior to changing parameters for valve dynamics a number
of items are to be checked, see below The pneumatic output
can be approached directly without controller via Menu 7
and the valve movement may be assessed
For behavior A) check:
1 Is the Proportionate gain P (Menu 6 1) or P  (Menu 6 2)
too small?
Remedy: Increase parameters according to chart 4
2 Is the air pressure high enough to possibly overcome
trouble-free the actuator spring force and friction
(dimensioning)?
Remedy: Increase the air pressure
3 Is the actuator volume high, possibly requiring an
increased air capacity for fast valve movement?
Remedy: Through booster, see accessories
4 Was AUTOSTART performed in Menu 2 and did messages
8 or 9 occur?
Remedy: AUTOSTART in Menu 2 or observe information
in table
5 Has the parameter for the positioning time been set at a
value too high?
Remedy: Decrease both parameters T63 in Menu 6 5 or
6 6
6 Is valve packing too tight resulting in a very high friction?
7 Is the supply air filter blocked?
Remedy: See "Supply Filter Replacement" on page 54
8 Has the supply air been contaminated by small oil drops
or particles or are pneumatic parts possibly blocked?
Remedy: Exchange of pneumatic parts; possibly use a
suitable air supply station
For behaviors B) and C) check:
1 Has the air supply pressure been set too high?
Remedy: Reduce pressure or install pressure reducer
2 Is the proportional amplification in Menu 6 1 or 6 2 too
high? The values can possibly be at Code 15
Remedy: Reduce the amplification
3 Is the air capacity possibly too high, for instance, through
spool valve or booster?
Remedy: Work, if necessary, without booster or use
version without spool valve
Changing valve dynamics during behavior A):
If valve has a high friction (for example, often the case in
small rotary actuators due to low air supply pressure or due
to a valve seat packing which is too tight) then the valve
position gets stuck after a setpoint jump and possibly is
recontrolled via the resetting time Tn, possibly after quite
some time has elapsed
Page 47
Startup
August 2014 POS-UM-00009-EN-02