Siemens SIMATIC S7-1200 - Page 651

Technology instructions
10.2 PID control
S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
651
Setting
TO-DB parameter
Data
type
Value range
Description
1
The field displays "s" (seconds) as the time units.
2
Only available if you check "Enable manual entry” in PID parameters ("Re-
tain.CtrlParams.SetByUser" = TRUE).
3
Unit of measurement is displayed at the end of the field as selected in “Basic settings” view.
4
Only available if you check/select the following items: "Enable manual entry” in PID parameters
("Retain.CtrlParams.SetByUser" = TRUE), “Activate output (cooling)” in “Basic settings” view
("Config.ActivateCooling" = TRUE), and “PID parameter switchover” in “Output settings” view
(Config.AdvancedCooling = TRUE).
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: