Y_YA_PI_Control
PI control block calculates an "error" value as the difference between a measured process variable and a desired set point, or reference. This error is used to calculate a control output which can be added to the control variable to drive the measured process variable towards the reference value. PI Parameters must be adjusted to allow the process to provide the proper ControlOutput for a given error situation. This block uses proportional and integral components in the control output calculation. This block does not have derivative gain adjustment.
Parameters:
| * | Parameter | Data Type | Description | Default |
|---|---|---|---|---|
| VAR_INPUT | ||||
| B | Enable | BOOL | The function will continue to execute every scan while Enable is held high and there are no errors. | FALSE |
| V | PIParameters | Yt_YA_PIStruct | Structure containing all the information for PI control block to operate | N/A |
| V | Reference | LREAL | Setpoint for the PID control loop. | LREAL#0.0 |
| V | ProcessValue | LREAL | Real world value to be compared with the Reference in the control loop | LREAL#0.0 |
| VAR_OUTPUT | ||||
| B | Valid | BOOL | Indicates that the function is operating normally and the outputs of the function are valid. | |
| V | ControlOutput | LREAL | Output value from the PID control block. The range of values will be governed by the PID parameters, especially the upper and lower limit. | |
| B | Error | BOOL | Set high if an error has occurred during the execution of the function block. This output is cleared when 'Execute' or 'Enable' goes low. | |
| E | ErrorID | UINT | If Error is true, this output provides the Error ID. This output is reset when 'Execute' or 'Enable' goes low. | |
| E | AtLimit | BOOL | AtLimit becomes TRUE if the calculated ControlOutput is less than the lower limit or if it is greater than the upper limit as specified in the PIParameter structure |
|
Error Description
See the
Function Block ErrorID List