Siemens SIMATIC S7-1200 Function Manual page 256

Instructions
9.1 PID_Compact
Tag
CancelTuningLevel
SubstituteOutput
SetSubstituteOutput
Config.InputPerOn
Config.InvertControl
Config.InputUpperLimit
Config.InputLowerLimit
256
Data type Default
REAL 10.0
REAL 0.0
BOOL TRUE
BOOL TRUE
BOOL FALSE
REAL 120.0
REAL 0.0
Description
Permissible fluctuation of setpoint during tuning. Tun-
ing is not canceled until:
Setpoint > CurrentSetpoint + CancelTuningLevel
•
or
Setpoint < CurrentSetpoint - CancelTuningLevel
•
Substitute output value
When the following conditions are met, the substitute
output value is used:
An error has occurred in automatic mode.
•
SetSubstituteOutput = TRUE
•
ActivateRecoverMode = TRUE
•
If SetSubstituteOutput = TRUE and ActivateRecover-
Mode = TRUE, the substitute output value configured
is output as long as an error is pending.
If SetSubstituteOutput = FALSE and ActivateRecov-
erMode = TRUE, the actuator remains at the current
output value as long as an error is pending.
If ActivateRecoverMode = FALSE, SetSubstituteOut-
put is not effective.
If SubstituteOutput is invalid (ErrorBits = 20000h), the
substitute output value cannot be output.
If InputPerOn = TRUE, the Input_PER parameter is
used. If InputPerOn = FALSE, the Input parameter is
used.
Invert control logic
If InvertControl = TRUE, an increasing control devia-
tion causes a reduction in the output value.
High limit of the process value
Input and Input_PER are monitored to ensure adher-
ence to this limit.
At the I/O input, the process value can be a maximum
of 18% higher than the standard range (overrange).
This pre-assignment ensures that an error is no longer
signaled due to a violation of the "Process value high
limit". Only a wire-break and a short-circuit are recog-
nized and PID_Compact reacts according to the con-
figured reaction to error.
InputUpperLimit > InputLowerLimit
Low limit of the process value
Input and Input_PER are monitored to ensure adher-
ence to this limit.
InputLowerLimit < InputUpperLimit
Function Manual, 03/2017, A5E35300227-AC
PID control