Allen-Bradley 2080-LC20-20QBB User Manual page 189

Rockwell Automation Publication 2080-UM005E-EN-E - March 2018
PID Arguments
Parameter Parameter
Type
CVMin Input
CVMax Input
Gains Input
Control Input
Llnit Input
Active Output
CV Output
AbsoluteError Output
Error Output
ErrorID Output
GAIN_PID Data Type
Parameter Parameter
Type
Kc Input
Data Type Description
REAL Control value minimum limit.
If CV < CVMin, then CV = CVMin.
If CVMin > CVMax, and error occurs.
REAL Control value maximum limit.
If CV > CVMax, then CV = CVMax.
If CVMax < CVMin, an error occurs.
PID_GAIN Gains of PID for controller.
S
Use the PID_GAINS data type to configure the Gains
parameter.
BOOL Control direction of the process:
TRUE = Direct acting, such as Cooling.
FALSE = Reverse acting, such as Heating.
BOOL Reserved for future use.
BOOL Status of the PID controller:
TRUE = PID state is running.
FALSE = PID state is stopped.
REAL The control value output.
If any error occurred, CV is 0.
REAL Absolute error is the difference between process
value (PV) and setpoint (SV) value.
BOOL Indicates the existence of an error condition.
TRUE = PID has an error.
FALSE = PID has no errors.
USINT A unique numeric that identifies the error. The errors
are defined in PID error codes.
Data Type Description
REAL Controller gain for PID.
Proportional and Integral are dependent on this gain
(>= 0.0001).
Increasing Kc improves response time but also
increases overshoot and oscillation of the PID.
If Kc is invalid, an error occurs.
PID Function Blocks Appendix D
179