Function block - Limit the ascendance or descendance of a signal
IN : REAL
Input
signal
ASC :
REAL Maximum
ascendance during time base
DSC :
REAL Maximum
descendance during time base
TM :
TIME Time
base
RST : BOOL Reset
OUT : REAL Ramp signal
Parameters are not updated constantly. They are taken into
account when only:
- the first time the block is called
- when the reset input (RST) is TRUE
In these two situations, the output is set to the value of IN
input.
ASC and DSC give the maximum ascendant and descendant growth
during the TB time base.
Both must be expressed as positive numbers.
In LD language, the operation is executed only if the input rung (EN) is TRUE. The output rung (ENO) keeps the same value as the input rung.
(* MyRamp is a declared instance of RAMP
function block *)
MyRamp (IN, ASC, DSC, TM, RST);
OUT := MyBlinker.OUT;
(* The function is executed only if EN is
TRUE *)
(* ENO keeps the same value as EN *)
(* MyRamp is a declared instance of RAMP
function block *)
Op1: CAL MyRamp (IN, ASC, DSC, TM, RST)
LD MyBlinker.OUT
ST OUT