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How do I move from a SCADAPack PIDA function block to a PIDFF function block

Users of SCADAPacks familiar with the PIDA function block in ISaGRAF 3.55, Workbench 6.x, and Telepace Studio will find that the PIDFF function block for the SCADAPack 57x can be used.

The PIDFF function block can be added in the SCADAPack x70 Logic Editor (launched from RemoteConnect).  Once the function block has been added finding related parameters between the PIDFF and PIDA blocks becomes important.  
PIDA Parameter PIDFF Parameter Notes
pv pv Process value
sp sp Setpoint
gain para_PIDFF->kp Proportional Gain
reset para_PIDFF->ti reset or integral action.  Parameter changes from a real to a time variable
rate para_PIDFF->td rate or derivative action.  Parameter changes from a real to a time variable
deadband para_PIDFF->dband Deadband
full para_PIDFF->out_max Maximum output value
zero para_PIDFF->out_min Minimum output value
cycleTime   Parameter no longer exists.  Calculation takes place on every PIDFF cycle
auto man_auto auto mode selection
outManual   Parameter no longer exists.  When using a PIDFF block write to the output variable when in manual mode
out out Calculated output of the PID block.  
  outd Change in output this scan
  para_PIDFF->pv_inf The minimum permitted pv to be used
  para_PIDFF->pv_sup The maximum permitted pv to be used

PIDFF parameters starting with para_PIDFF-> will need to be set from within the Para_PIDFF structure that is connected to the PARA input.

The PIDFF function block offers more functionality than was previously available in the PIDA function block.  This additional information can be found in the help installed with the SCADAPack x70 Logic Editor.

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