FB_CTRL_I
The function block provides an I-transfer element in the functional diagram.
Transfer function:
VAR_INPUT
VAR_INPUT
fIn : FLOAT;
fManSyncValue : FLOAT;
bSync : BOOL;
eMode : E_CTRL_MODE;
bHold : BOOL;
END_VAR
fIn : Input of the I element.
fManSyncValue : Input to which the I-element can be synchronised, or whose value is the present at the output in Manual Mode.
bSync : A rising edge at this input sets the integrator to the value fManSyncValue.
eMode : Input that specifies the block's operating mode.
bHold : A TRUE at this input holds the integrator fixed at the current value, independently of the input fIn.
VAR_OUTPUT
VAR_OUTPUT
fOut : FLOAT;
bARWactive : BOOL;
eState : E_CTRL_STATE;
eErrorId : E_CTRL_ERRORCODES;
bError : BOOL;
END_VAR
fOut : Output of the I element.
bARWactive : A TRUE at this output signals that the integrator is being restricted.
eState : State of the function block.
nErrorID : Returns the ADS error number when the bError output is set.
bError: Becomes TRUE, as soon as an error occurs.
VAR_IN_OUT
VAR_IN_OUT
stParams : ST_CTRL_I_PARAMS;
END_VAR
stParams : Parameter structure of the I element. This consists of the following elements:
TYPE ST_CTRL_I_PARAMS
:
STRUCT
tCtrlCycleTime : TIME := T#0ms; (* controller cycle time
*)
tTaskCycleTime : TIME := T#0ms; (* task cycle time
*)
tTi : TIME := T#0ms; (* integral action time
Ti *)
fOutMaxLimit : FLOAT := 1E38; (* maximum output limit
*)
fOutMinLimit : FLOAT := -1E38; (* minimum output limit
*)
END_STRUCT
END_TYPE
tCtrlCycleTime : Cycle time with which the control loop is processed. This must be greater than or equal to the TaskCycleTime. The function block uses this input value to calculate internally whether the state and the output values have to be updated in the current cycle.
tTaskCycleTime : Cycle time with which the function block is called. If the function block is called in every cycle this corresponds to the task cycle time of the calling task.
tTi : Integration time of the I element.
fOutMaxLimit : Upper limit at which integration is halted (ARW measure). Reaching this limit is indicated by a TRUE at the bARWActive output.
fOutMinLimit : Lower limit at which integration is halted (ARW measure). Reaching this limit is indicated by a TRUE at the bARWActive output.