Rockwell Automation DeviceLogix System User Manual - Manual (Page 28)

28 Publication RA-UM003B-EN-P - February 2010
Chapter 2 Navigate the Function Block Editor Interface
The PID function has Enable In and Process Variable as inputs, and
Enable Out and Control Variable as outputs, as described in the
following tables.
The PID function also provides four parameters that you can modify
as needed:
• Tuning
• Configuration
• Scaling
• Status
Tuning Parameters
Tuning Parameters allow you to set the PID algorithm parameters.
Input Type Default Description
Enable In BOOL 1 Enable In
PV REAL 0.0 Process Variable
Output Type Default Description
Enable Out BOOL 0 Enable Out
CV REAL 0.0 Control Variable
Parameter Type Range Default Description
Setpoint (SP) REAL 0.0 Desired control point of the process variable. It
should be scaled in the engineering unit.
Set Output % REAL 0.0 ~ 100.0 0.0 PID output for the manual set output mode. Use
this value to prevent bumps in control when
switching control mode back to automatic.
Output Bias % REAL 0.0 ~ 100.0 0.0 Output bias percentage
Control Gain (K
c
) REAL 0.0 Controller gain
Reset Time (T
i
) REAL 0.0 Reset time
Rate Time (T
d
) REAL 0.0 Rate time
Station Mode BOOL 0 Indicates the station mode:
• 0 = Manual
• 1= Automatic