Siemens SIMATIC S7-1200 Function Manual page 429

Tag
Retain.CtrlParams.Cool
.ControlZone
Retain.CtrlParams.Cool
.DeadZone
Note
Change the tags listed in this table in "Inactive" mode to prevent malfunction of the PID
controller.
See also
PID_Temp ActivateRecoverMode tag (Page 442)
PID_Temp Warning tag (Page 444)
Multi-zone controlling with PID_Temp (Page 199)
PID control
Function Manual, 03/2017, A5E35300227-AC
Data type Default
REAL 3.402822e+38
REAL 0.0
Description
Active control zone width for cooling
The control zone for cooling is switched off with
Cool.ControlZone = 3.402822e+38.
Cool.ControlZone is only set automatically during pretun-
ing cooling or pretuning heating and cooling if PIDSelf-
Tune.SUT.TuneRuleCool = 2 is selected as method of the
parameter calculation.
Cool.ControlZone is retentive.
Only effective if the cooling output and PID parameter
switching are activated (Config.ActivateCooling = TRUE
and Config.AdvancedCooling = TRUE).
Cool.ControlZone > 0.0
Active dead zone width for cooling (see PID parameters
(Page 174))
The dead zone for cooling is switched off with
Cool.DeadZone = 0.0.
Cool.DeadZone is not set automatically or adjusted during
tuning. You must correctly configure Cool.DeadZone
manually.
When the dead zone is switched on, the result can be a
permanent control deviation (deviation between setpoint
and process value). This can have a negative effect on
fine tuning.
Cool.DeadZone is retentive.
Only effective if the cooling output and PID parameter
switching are activated (Config.ActivateCooling = TRUE
and Config.AdvancedCooling = TRUE).
Cool.DeadZone ≥ 0.0
Instructions
9.3 PID_Temp
429