FUNCTION_BLOCK RAMP_INT
Limits the slope of a value to a certain value
The limitation of the slope is given by the maximum ascend ASCEND and the maximum descend DESCEND and a time base TIMEBASE defining the time for which ASCEND or DESCEND hold.
Note
It is not necessary to readjust the controller parameters (KP, TN, TV) if the cycle time changes.
Example
InOut:
|
Scope |
Name |
Type |
Comment |
|
Input |
IN |
INT |
Input value |
|
ASCEND |
INT |
Limitation of acceleration: Maximum ascent per time base Example: ASCEND := 25 and TIMEBASE := T#1s => Maximum ascent of 25 increments per second |
|
|
DESCEND |
INT |
Limitation of deceleration: Maximum descent per time base (DESCEND > 0) Example: DESCEND := 20 and TIMEBASE := T#500ms => Maximum ascent of 20 increments in 500 milliseconds |
|
|
TIMEBASE |
TIME |
Reference for ASCEND/DESCEND : t#0s : ASCEND/DESCEND defined per call else : ASCEND/DESCEND defined per specified time If TIMEBASE = t#0s, then the time base is equal to the task cycle time. In this case the limitation refers to a task cycle. Usually this corresponds exactly to one call of the function block RAMP_INT. Note If the time base TIMEBASE is smaller than the task cycle time, then this will lead to a violation of the sampling theorem and might result in a loss of information in the output signal. |
|
|
RESET |
BOOL |
Reset of the function block TRUE: Stops the internal calculation and reinitializes the function block. The last calculated output value in OUT is maintained in order to start the internal calculation with it at the next restart of the function block. FALSE: Outputs the smoothed input signal at output OUT. |
|
|
Output |
OUT |
INT |
Function value with limited ramp The value gets stored internally and will be used for the calculation of the ascent and the descent of the input signal. |
