Fanuc Series 15i/150i-MA (Programming) Operators Manual

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19.9.5 Synchronization Ratio Specification Range
The programmed ratio (synchronization ratio) of a movement along the
slave axis to a movement along the master axis is converted to a
detection unit ratio inside the NC. If such converted data (detection
unit ratio) exceeds a certain allowable data range in the NC,
synchronization cannot be established correctly, and an alarm (PS0596)
is issued.
Even when a programmed master axis movement and a programmed
slave axis movement are within specifiable ranges, a detection unit ratio
obtained by conversion can exceed the allowable range, thus resulting
in an alarm.
Let K be a synchronization ratio. The internal data corresponding K is
the amount of slave axis movement (Kn) represented in the detection
unit divided by the amount of master axis movement (Kd) represented
in the detection unit; this fraction is represented as Kn/Kd (reduced to
its lowest terms) as indicated below.
K=Kn/Kd= Amount of slave axis movement represented in the
detection unit/Amount of master axis movement represented in the
detection unit
Kn and Kd must lie within the following ranges:
-2147483648 Kn 2147483647
1 Kd 65535
When Kn or Kd exceeds its allowable range above, an alarm is issued.
In conversion to the detection unit, when the CMR (command
multiplication: parameter 1820) is a fraction or when inch/millimeter
conversion is used, the fraction is directly converted without
modification so that no error can occur in the conversion of specified
amounts of movement.
During conversion, the amount of movement is multiplied by 254/100
for inch input on a millimeter machine, and 100/254 for metric input on
an inch machine. Thus, Kn and Kd can become large numbers. If a
synchronization ratio cannot be reduced to its lowest terms, an alarm
condition is likely to occur.
- Based on the controlled axis configuration described in Subsec. II-19.9.3,
suppose that the spindle and V-axis are as follows:
Spindle pulse coder :
72000pulse/rev(4 pulses for one A/B phase cycle)
C-axis least command increment: 0.001 degree
C-axis CMR : 5
V-axis least command increment: 0.001mm
V-axis CMR : 5
Then, the C-axis detection unit is 0.0002 degree. The V-axis detection
unit is 0.0002 mm. In this case, the synchronization ratio (Kn, Kd) is
related with a command as indicated below. Here, let Pm and Ps be the

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