GPS-X Technical Reference

343 Tools Object
Control Variable Parameters
Controller (ON – OFF): A value of ON indicates that the controller is active; a value of
OFF indicates that the controller is not active (i.e., not adjusting the manipulated
variable). This should not be confused with the `on' and `off' states of the on/off
controller.
Controller sampling time: This parameter determines the length of time between
controller executions. A high value (corresponding to a long interval between executions)
may be appropriate for slower processes (e.g., MLSS control using the sludge wastage
rate), while other processes may require faster sampling frequencies.
Control variable (CV) with label: The cryptic name of the variable to be controlled.
Upper bound: The upper bound on the controlled variable. If the value of the controlled
variable exceeds this value, then the value of the manipulated variable will be set to its
low setting.
Lower bound: The lower bound on the controlled variable. If the value of the controlled
variable is less than this value, then the value of the manipulated variable will be set to its
high setting.
Manipulated Variable Parameters
Manipulated variable (MV) with label: The cryptic name of the manipulated variable.
MV setting when CV is at low limit: The value of the manipulated variable is set to this
value when the value of the controlled variable is less than its lower bound.
MV setting when CV is at high limit: The value of the manipulated variable is set to
this value when the value of the controlled variable exceeds its upper bound.
MV initial value: The value to assign to the manipulated variable until the controlled
variable crosses either its upper or lower bound.
GPS-X Technical Reference