FB_CTRL_PT1
The function block provides a PT1 transfer element in the functional diagram.
Transfer function
Step response
VAR_INPUT
VAR_INPUTEND_VAR
fIn : FLOAT;
fManSyncValue : FLOAT;
bSync : BOOL;
eMode : E_CTRL_MODE;
bHold : BOOL;
Name | Type | Description |
|---|---|---|
fIn | FLOAT | Input value of the PT1 element |
fManSyncValue | FLOAT | Input value to which the PT1 element can be set, or that is issued at the output in manual mode. |
bSync | BOOL | A rising edge at this input sets the PT1-element to the value "fManSyncValue". |
eMode | E_CTRL_MODE | Input that specifies the operation mode of the function block. |
bHold | BOOL | A TRUE at this input will hold the internal state (and therefore also the output) constant at its current value, independently of the input value. |
VAR_OUTPUT
VAR_OUTPUT
fOut : FLOAT;
eState : E_CTRL_STATE;
eErrorId : E_CTRL_ERRORCODES;
bError : BOOL;
END_VARName | Type | Description |
|---|---|---|
fOut | FLOAT | Output of the PT1 element |
eState | E_CTRL_STATE | State of the function block |
eErrorId | E_CTRL_ERRORCODES | Supplies the error number when the output |
bError | BOOL | Becomes TRUE, as soon as an error occurs. |
VAR_IN_OUT
VAR_IN_OUT
stParams : ST_CTRL_PT1_PARAMS;
END_VARName | Type | Description |
|---|---|---|
stParams | ST_CTRL_PT1_ | Parameter structure of the PT1 element |
stParams consists of the following elements:
TYPE
ST_CTRL_PT1_PARAMS :
STRUCT
tCtrlCycleTime : TIME := T#0ms;
tTaskCycleTime : TIME := T#0ms;
fKp : FLOAT := 0;
tT1 : TIME := T#0ms;
END_STRUCT
END_TYPEName | Type | Description |
|---|---|---|
tCtrlCycleTime | TIME | 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 | TIME | 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. |
fKp | FLOAT | Controller amplification / transfer coefficient |
tT1 | TIME | time constant |