Lenze EVS93 Series, System Manual

Page: 192 / 386

Function library
Function blocks
3.2.49 Extrapolation (EXTPOL1)
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l
EDSVS9332K−EXT EN 4.0
3.2.49 Extrapolation (EXTPOL1)
Optimisation of running features
E X T P O L 1
E X T P O L 1 - P H O U T
C 1 3 7 5 / 1
E X T P O L 1 - P H I N
C 1 3 7 4 / 1
C 1 3 7 1 / 1
E X T P O L 1 - A I N
C 1 3 7 0 / 1
E X T P O L 1 - S T A T
Signal Source Note
Name Type DIS DIS format CFG List
EXTPOL1−AIN d 1371/1 bin 1370/1 Speed input
EXTPOL1−PHIN ph 1375/1 ph 1374/1 Position input
EXTPOL1−STAT d 13451 − − − HIGH = extrapolation on
LOW = new data at input PHIN
EXTPOL1−PHOUT ph 13451 − − − Extrapolated position of input PHIN
The function block EXTPOL1 is used when position information is exchanged between master and
slave using a bus system.
The transfer cycle via a bus system is often longer than 1 ms, especially if
l for instance, a PLC or an industrial PC is connected to the bus
l
the baud rate is < 1Mbaud (e.g. with cable lengths > 25 m)
The short response time required between setpoint and actual value of the controller is prolonged
by the bus load. Especially when the position is changed, a linear speed characteristic is converted
into a step−like characteristic. The suddenly changing speed results in corresponding torque peaks
in all drive elements connected.
The function block EXTPOL1 smoothens this ’step’ character by ’fine−interpolation’ between the
steps (see function block symbol). The improved smoothness of running can even be heard.