Fagor CNC 8055, Manual

Page: 76 / 166

N
EW
F
EATURES
(S
OFT
M: 9.0
X
)
CNC 8
0
5
5
/ CNC 8
0
5
5
i
Page 16 of 106
Prior considerations
Bear in mind that:
• Each tandem master axis can only have one tandem slave axis.
• A pre-load may be applied between both motors.
• Each motor may have a different rated torque.
• Each motor may be rotating in the opposite direction to the other
one.
• The torque distribution between both motors may be different from
a 1:1 ration. For example on motors with different rated torques.
• It is not possible to share feedback or velocity commands using the
switch parameters on axes having a tandem configuration.
4.1 Block diagram
The block diagram of the tandem control system shows the tandem
master axis with its tandem slave axis.
The block diagram for a gantry machine consists of the same two
diagrams as the one shown in the figure.
General description. Position and velocity loops.
The block diagram shows an area for the drive and another one for the
CNC that covers the position loop and the control of the tandem.
• The position loop only closes with the position of the master axis
of the tandem. The velocity command of the tandem master axis
is sent to the tandem slave axis closing the velocity loop.
• The tandem control modifies the velocity command of the master
axis and of the slave axis depending on the torque distribution and
the selected pre-load.
The PROGAIN, FFGAIN and DERGAIN values of the master axis are
applied to the slave axis.