
4. SERVO FUNCTION DETAILS B-65150E/04
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(3) Changing the torque output polarity with the full preload function
When the full preload function is used together with synchronous
tandem control as shown in Fig. 4.17.7 (e), set the torque output
polarity with the parameter bit SPPCHG (No. 1952#4, No. 2008#4) so
that the main motor on the master side and that on the slave side
produce torques in the same direction.
Table 4.17.7(a) Example of setting (1)
Synchronous
axis
Tandem axis Motor name SPPCHG Preload value
Master Main X
m
0+
Sub X
2
−
Slave Main X
3
1 −
Sub X
4
+
Another example is given below.
Table 4.17.7(b) Example of setting (2)
Synchronous
axis
Tandem axis Motor name SPPCHG Preload value
Master Main X
m
1 −
Sub X
2
+
Slave Main X
3
0+
Sub X
4
−
CAUTION
In the example shown in Fig. 4.17.7 (e), the main
motor on the master side faces the main motor on the
slave side. This means that if the same torque output
polarity is set, the two main motors will produce
opposing torques, resulting in twisting of the machine.
In such a case, set the output polarities so that the
output polarity on the master side is opposite to that
on the slave side.
That is, to prevent the machine from twisting, the
output polarities of the motors must be
determined according to the structure of the
machine.