Tandem Axis Configuration. Machine Parameters - Fagor CNC 8060 Installation Manual

I n s t a l l a t i o n m a n u a l .
11.2.1

Tandem axis configuration. Machine parameters.

The tandem pairs of the system are configured by machine parameters. Each tandem pair
has the following general machine parameters to configure it.
Parameter.
TANDEM
MASTERAXIS
SLAVEAXIS
TORQDIST
PRELOAD
PRELFITI
TPROGAIN
TINTIME
TCOMPLIM
Axes or spindles of the tandem system.
A tandem system can consist of a pair of linear axes, rotary axes or spindles. The pair of
axes or spindles making up the tandem system is set by machine parameters MASTERAXIS
and SLAVEAXIS inside the TANDEM table. The axes must be previously defined in
parameter AXISNAME and the spindles in parameter SPDLNAME.
The master motor of the tandem, besides generating torque, it is in charge of positioning.
The slave motor only provides torque.
The CNC closes the position loop only with the position of the master axis of the tandem.
The velocity command of the master axis/spindle of the tandem is also sent to the slave
axis/spindle of the tandem closing the velocity loop. The tandem control changes the velocity
command of the master axis/spindle and that of the slave axis/spindle according to the torque
distribution and the selected preload.
Type of servo system and feedback.
Tandem axes or spindles must be velocity-Sercos; if not, both axes will move, but it will not
be a tandem system. All the axes that will be interpolated with the tandem axis must also
operate in velocity-Sercos mode.
In a tandem system, the master axis or spindle can carry either external or internal feedback.
The slave axis or spindle normally uses internal feedback. The tandem does not admit
combined feedback (external+internal).
Considerations for tandem spindles.
• The PLC must enable and disable the SPENA(axis) and DRENA(axis) signals of the
master and slave spindles at the same time.
• Both spindles must be in the same gear (range).
• To control the tandem spindle from the PLC, for example in a gear change, it is only
necessary to activate the marks PLCCNTL, SPDLEREV and SANALOG of the master
spindle.
Torque load distribution in the tandem.
The torque distribution sets the torque percentage supplied by each motor to obtain the total
necessary torque in the tandem. The torque distribution in the tandem is defined with
parameter TORQDIST that indicates the percentage to be provided by the master motor. The
difference between the value of this parameter and 100% is the percentage applied to the
slave motor.
The torque distribution between both motors may be different from 1:1 ratio; for example,
on motors whose rated torque is different. If the motors are identical and they're both
supposed to output the same torque, this parameter should be set to 50%.
Meaning.
Table of tandem axes or spindles.
Master or main axis/spindle.
Slave axis/spindle.
Torque distribution.
Preload between both motors.
Filter time to apply the preload.
Proportional gain (Kp) for the tandem.
Integral gain (Ki) for the tandem.
Compensation limit.
11.
CNC 8060
CNC 8065
(R : 1709)
EF
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