
B–63523EN–1/03
1. AXIS CONTROL
331
Note the following points when specifying parameters for the electronic
gear box.
1. Arrange the controlled axes such that a slave axis appears before a
dummy axis.
Servo axis
Axis name number
(No.1023)
X1
Y2
C (dummy axis) 3
C (slave axis) 4
Example of correct setting
Servo axis
Axis name number
(No.1023)
X1
Y2
C (slave axis) 3
C (dummy axis) 4
Example of incorrect setting
(Example)
2. Do not use a name which is usually not allowed to be used as an axis
address, such as D.
3. Specify the same values for an EGB slave axis and an EGB dummy
axis in the following parameters.
1004#7 Ten times minimum input increment
1001#0 Inch/metric switching (rotation axis/linear axis)
1006#1 Shape of machine coordinate system (rotation axis/linear
axis)
1006#2 Shape of machine coordinate system for pitch error
compensation (rotation axis/linear axis)
1420 Rapid traverse rate
1421 Rapid–traverse override F0 speed
1820 Command multiplication
4. Specify the amount of travel per rotation about a rotation axis for a
slave axis in a parameter No. 1260.
5. Make the specification for a dummy axis in the following way.
1807#3, 1815#1 Whether to use separate detectors. Although an
EGB dummy axis uses the interface of a separate
detector, set these parameters to 0.
6. If the following parameters are not specified, an alarm (SV 417 servo
parameter invalid) may be generated. In such a case, make the
specification as described below.
20XX Specify the same value for both a slave axis and a dummy
axis.
2084, 2085 Flexible feed gear.
Set parameters Nos. 2084 and 2085 to 1 for the dummy
axis.
7. Specify as large a feed–forward coefficient as possible to reduce the
synchronization error. For details of parameter setting, see
Feed–forward setting of Geometric error suppression function in
FANUC AC SERVO MOTOR ai series Parameter Manual
(B–65270EN) or FANUC AC SERVO MOTOR a series Parameter
Manual (B–65150E).