Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 664)

L-force | PLC Designer
PLC Designer Libraries
662 DMS 3.2 EN 02/2011 TD29

19.2.3 Mathematic Auxiliary Functions
DERIVATIVE
Provided by util.lib.
This function block approximately determines the local derivation.
The function value is delivered as a REAL variable by using IN. TM contains the time
which has passed in msec in a DWORD and the input of RESET of the type BOOL allows
the function block to start anew through the delivery of the value TRUE.
The output OUT is of the type REAL.
In order to obtain the best possible result, DERIVATIVE approximates using the last
four values, in order to hold errors which are produced by inaccuracies in the input
parameters as low as possible.
Block in FBD:
INTEGRAL
Provided by util.lib.
This function block approximately determines the integral of the function.
In an analogue fashion to DERIVATIVE, the function value is delivered as a REAL
variable by using IN. TM contains the time which has passed in msec in a DWORD and
the input of RESET of the type BOOL allows the function block to start anew with the
value TRUE.
The output OUT is of the type REAL.
The integral is approximated by two step functions. The average of these is delivered
as the approximated integral.