
1.AXIS CONTROL B-63943EN-1/02
- 316 -
2372
Serial EGB exponent specification (γ)
[Input type] Parameter input
[Data type] Word axis
[Valid data range] 0 to 15
By setting a value in this parameter, it is possible to internally
multiply the value of parameter No. 7772 or 7782 by 2
γ
.
With a high resolution serial detector, the number of pulses per
rotation is large, causing the denominator of the synchronization
coefficient (K
1
) to become large, which may fall outside the valid
range. By providing 2's exponent component for the
number-of-pulses setting per rotation about the workpiece axis, it is
possible to keep the denominator of the EGB coefficient low.
・Valid range of a synchronization coefficient
A synchronization coefficient is internally represented using a fraction
number (
K
n
/K
d
) to eliminate an error. The formula below is used for
calculation.
α
β
T
L
K
K
d
n
×==ientationefficSynchroniz
L: Number of teeth
T: Number of hob threads
α: Number of pulses of the position detector per rotation
about the EGB master axis (parameter No. 7772)
β: Number of pulses of the position detector per rotation
about the EGB slave axis (parameter No. 7773)
K
n
/K
d
is a value resulting from reducing the right side of the above
formula, but the result of reduction is subject to the following
restrictions:
-2147483648≦
K
n
≦2147483647
1≦
K
d
≦65535
If this condition is not satisfied, an alarm is generated when G81 is
issued.
If the number of pulses per rotation about the master axis is large, this
condition may not be satisfied. In such a case, use this parameter.
If using a serial detector, set the number of post-FFG pulses. If the
exponent specification is used, α x 2
γ
means the "number of pulses of
the position detector per rotation about the master axis".
If a serial type detector is used as the master axis detector, the
relationship between master axis feedback (in detector pulse units) and
the move command to the slave axis (Detection unit in the NC) is as
follows:
)(
2
)( feedbackmasteraxis
M
N
T
L
ovecommandslaveaxism ××
×
×
γ
α
β
=