User Manual

PID is easy
8.6 Configuring the PID controller
Easy Book
188 Manual, 03/2014, A5E02486774-AF
8.6
Configuring the PID controller
The parameters of the technology object determine the operation of the PID
controller. Use the icon to open the configuration editor.
Table 8- 9 Sample configuration settings for the PID_Compact instruction
Settings
Description
Basic
Controller type
Selects the engineering units.
Invert the control logic Allows selection of a reverse-acting PID loop.
• If not selected, the PID loop is in direct-acting mode and the output of PID loop
increases if input value < setpoint.
• If selected, the output of the PID loop increases if the input value > setpoint.
Enable last mode after
CPU restart
Restarts the PID loop after it is reset or if an input limit has been exceeded and
returned to the valid range.
Input Selects either the Input parameter or the Input_PER parameter (for analog) for the
process value. Input_PER can come directly from an analog input module.
Output Selects either the Output parameter or the Output_PER parameter (for analog) for
the output value. Output_PER can go directly to an analog output module.
Process
value
Scales both the range and the limits for the process value. If the process value goes below the low limit or
above the high limit, the PID loop goes to inactive mode and sets the output value to 0.
To use Input_PER, you must scale the analog process value (input value).