[FISHER-) 
Configuration  5-47 
Use  FCODE  135  to  select  status  of  the  Autotuner  function 
Function  FCODE 
Option  No  Default  Selected 
V&X  Value 
Autotuner  135  Disabled  0  0 
Enabled  1 
Enabled,  break  on  alarm  2 
Use  FCODE  136  to  select  maximum  initial  output  signal  change.  By 
selecting  a  maximum  output  signal  level  during  tuning,  the  user  can 
limit  the  output  swing  generated  by  the  controller.  The  user  is 
reminded  that  the  controller  will  only  use  the  minimum  swing  required 
to  solve  for  PID.  For  a  majority  of  applications,  the  default  value  (10%) 
is  adequate. 
Function  FCODE  Option 
No  Default  Selected 
Value  V&K? 
Max  Output 
136 
10  Percent  1  1 
Signal  5  Percent  2 
Change 
3  Percent  3 
Set  a  low  output  signal  change  percentage  to  use  the  autotuner  for 
processes  with  moderate  deadtimes. 
Use  FCODE  137  to  select  controller  dynamics.  After  one  tuning  it  can 
be  used  to  change  the  dynamics  without  any  retuning.  Essentially  this 
FCODE  controls  the  damping  factor  of  the  function.  The  figure  shows 
the  dynamics  of the  four  options. 
Fast  Medium 
May  1991