HEIDENHAIN iTNC 530 HSCI - Page 645

1 – 646 HEIDENHAIN Service Manual iTNC 530 HSCI
Unlike operation with following error, the machine manufacturer sets the optimum k
v
factor for each
axis for operation with interpolating axes.
Position control
with velocity
semifeedforward
control
MP1396.x allows the operator to switch to velocity semifeedforward control.
Normally, work will be carried out using velocity feedforward. Velocity semifeedforward is activated,
for example, by an OEM cycle before roughing, in order to permit a higher following error and thereby
a higher velocity, combined with a lowered accuracy, in order to traverse corners.
Before finishing, another OEM cycle can be used to switch back to velocity feedforward, in order to
finish with the highest accuracy possible.
In order to use velocity semifeedforward, a factor must be entered for every axis in MP1396.x, where
values toward 0 control the following error more, and values toward 1 control the velocity feedforward
more.
As soon as a factor between 0.001 and 0.999 has been entered in MP1396.x, the k
V
factor from
MP1516.x becomes effective.
The values for position monitoring are interpolated according to the factor in MP1396.x between the
values for servo lag (MP1710.x, MP1720.x) and the values for velocity feedforward control (MP1410.x,
MP1420.x).
Note
Analog axes (control via CMA-H): For stationary axes, the integral factor has an additional effect
(MP1080.x). It produces an offset adjustment.
Digital axes: There is no offset. MP1080.x has no function.
Note
For axes that are interpolated with each other, the k
v
factors must be equal. In this case the smaller
k
v
factor determines the input value for these axes.
Feedback control with
following error (servo lag)
Feedback control with velocity
semifeedforward
Feedback control with
velocity feedforward
MP1391 bit x = 0
MP1392 bit x = 0
MP1396.x = nonfunctional
MP1391 bit x = 1
MP1392 bit x = 1
MP1396.x = 0.001 MP1396.x = 0.999
MP1391 bit x = 1
MP1392 bit x = 1
MP1396.x = 1