Stabilize/Optimize; Performance Tuner - Fisher FIELDVUE DVC6200 Instruction Manual

DVC6200 Digital Valve Controller
Table 4-3. Conditions for Modifying FIELDVUE DVC6200 Digital Valve Controller Parameters (Continued)
Parameters
Flash ROM Fail
Ref Voltage Fail
Drive Current Fail
Critical NVM Fail
Temp Sensor Fail
Press Sensor Fail
Tvl Sensor Fail
n—indicates parameter may be modified for instrument mode and protection shown.
In addition, you can select User Adjusted or Expert,
which allows you to modify tuning of the digital
valve controller. With User Adjusted, you specify
the proportional gain; an algorithm in the Field
4
Communicator calculates the velocity gain and
minor loop feedback gain. With Expert you can
specify the proportional gain, velocity gain, and
minor loop feedback gain.
Note
Use Expert tuning only if standard
tuning has not achieved the desired
results.
Stabilize/Optimize or Performance
Tuner may be used to achieve the
desired results more rapidly than
Expert tuning.
Table 4-5 provides tuning set selection guidelines
for Fisher and Baumann actuators. These tuning
sets are only recommended starting points. After
you finish setting up and calibrating the instrument,
you may have to select either a higher or lower
tuning set to get the desired response. You can
use the Performance Tuner to optimize tuning.
For an actuator not listed in the tables, you can
estimate a starting tuning set by calculating the
casing or cylinder volume. Then, in the tables, find
an actuator with the closest equivalent volume and
use the tuning set suggested for that actuator.
Tvl Prop Gain—Travel Proportional Gain is the
proportional gain for the travel control tuning set.
Changing this parameter will also change the
tuning set to Expert.
Tvl Velocity Gain—Travel Velocity Gain is the
velocity gain for the travel control tuning set.
Changing this parameter will also change the
tuning set to Expert.
Tvl MLFB Gain—Travel MLFB Gain is the minor
loop feedback gain for the travel control tuning set.
36
In Service/ In Service/
Config Protected Config Unprotected
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
- - - - - -
Changing this parameter will also change the
tuning set to Expert.
D Tvl Integ Enable—Yes or No. Enable the
integral setting to improve static performance by
correcting for error that exists between the travel
target and actual travel. Travel Integral Control is
enabled by default.
D Tvl Integ Gain—Travel Integral Gain is the
ratio of the change in output to the change in input,
based on the control action in which the output is
proportional to the time integral of the input.
D Stabilize/Optimize —Stabilize/Optimize
permits you to adjust valve response by changing
the digital valve controller tuning.
If the valve is unstable, select Decrease Response
to stabilize valve operation. This selects the next
lower tuning set (e.g., F to E). If the valve response
is sluggish, select Increase Response to make the
valve more responsive. This selects the next higher
tuning set (e.g., F to G).
If after selecting Decrease Response or Increase
Response the valve travel overshoot is excessive,
select Decrease Damping to select a damping
value that allows more overshoot. Select Increase
Damping to select a damping value that will
decrease the overshoot. When finished, select
done.
D Performance Tuner
The Performance Tuner is available for
instrument level AD, PD, and ODV.
The Performance Tuner is used to determine digital
valve controller tuning. It can be used with digital valve
controllers mounted on most sliding-stem and rotary
actuators, including Fisher and other manufacturers'
products. Moreover, because the performance tuner
can detect internal instabilities before they become
Out of Service/ Out of Service/
Config Protected Config Unprotected
- - -
- - -
- - -
- - -
- - -
- - -
- - -
Note
September 2010
n
n
n
n
n
n
n