Polynomial Evaluation Synfct - Siemens SINUMERIK 840Di sl Function Manual

2.4.5

Polynomial evaluation SYNFCT

Application
By applying an evaluation function in the action section of a synchronized action, it is
possible to read a variable, evaluate it with a polynomial and write the result to another
variable in synchronism with the machining process. This functionality can be used, for
example, to perform the following tasks:
• Feedrate as a function of drive load
• Position as a function of a sensor signal
• Laser power as a function of path velocity
SYNFCT() evaluation function
The function has the following parameters:
SYNFCT(
For definition of a polynomial, please see Chapter "FCTDEF".
Operating principle of SYNFCT
The polynomial identified by "Polynomial number" is evaluated with the value of the "Real-
time variable input". The result is then limited by maximum and minimum limits and assigned
to the "Real-time variable output".
Example
FCTDEF(1,0,100,0,0.8,0,0)
...
Synchronized action:
ID=1 DO SYNFCT(1,$AA_VC[U1], $A_INA[2])
For the 'Real-time variable output', it is possible to select variables that are included in the
machining process as follows:
• as an additive control factor (e.g. feedrate),
• as a multiplicative control factor (e.g. override),
• as a position offset
• directly
Synchronized actions
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
...
Polynomial number,
Real-time variable output,
Real-time variable input)
2.4 Actions in synchronized actions
; Definition of polynomial 1 is done
; the additive offset value of the axis U1 is
calculated in each interpolation cycle from
the analog input value 2 via polynomial 1
Detailed description
51