Siemens S7-1200 System Manual page 440

Technology instructions
9.2 PID control
PID start value control
You can edit the actual values of the PID configuration parameters so that the behavior of
the PID controller can be optimized in online mode.
Open the "Technology objects" for your PID controller and its "Configuration" object. To
access the start value control, click the "eyeglasses icon" in the upper left corner of the
dialog:
You can now change the value of any of your PID controller configuration parameters as
shown in the figure below.
You can compare the actual value to the project (offline) start value and the PLC (online)
start value of each parameter. This is necessary to compare online/offline differences of the
Technology object data block (TO-DB) and to be informed about the values that will be used
as current values on the next Stop-to-Start transition of the PLC. In addition, a compare icon
gives a visual indication to help easily identify online/offline differences:
The figure above shows the PID parameter screen with compare icons showing which
values are different between online and offline projects. A green icon indicates that the
values are the same; a blue/orange icon indicates that the values are different.
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S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG