Siemens SIMATIC S7-1200 Function Manual page 267

State / Mode Description of operating mode
4 Manual mode
In manual mode, you specify a manual output value in the ManualValue parameter.
You can also activate this operating mode using ManualEnable = TRUE. We recommend that you change
the operating mode using Mode and ModeActivate only.
The switchover from manual mode to automatic mode is bumpless. Manual mode is also possible when an
error is pending.
5 Substitute output value with error monitoring
The control algorithm is deactivated. The SetSubstituteOutput tag determines which output value is output
in this operating mode.
SetSubstituteOutput = FALSE: Last valid output value
•
SetSubstituteOutput = TRUE: Substitute output value
•
You cannot activate this operating mode using Mode = 5.
In the event of an error, it is activated instead of "Inactive" operating mode if all the following conditions are
met:
Automatic mode (Mode = 3)
•
ActivateRecoverMode = TRUE
•
One or more errors have occurred in which ActivateRecoverMode is effective.
•
As soon as the errors are no longer pending, PID_Compact switches back to automatic mode.
ENO characteristics
If State = 0, then ENO = FALSE.
If State ≠ 0, then ENO = TRUE.
Automatic switchover of operating mode during commissioning
Automatic mode is activated following successful pretuning or fine tuning. The following table
shows how Mode and State change during successful pretuning.
Cycle no.
0
1
1
n
n
PID_Compact automatically switches the operating mode in the event of an error.
PID control
Function Manual, 03/2017, A5E35300227-AC
Mode State Action
4 4 Set Mode = 1
1 4 Set ModeActivate = TRUE
4 1 Value of State is saved in Mode parameter
Pretuning is started
4 1 Pretuning successfully completed
3 3 Automatic mode is started
Instructions
9.1 PID_Compact
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