
4.DESCRIPTION OF PARAMETERS B-63950EN/02
- 106 -
least
command
increment
×
CMR
Error counter
DA
Converter
×
DMR
Position
detector
Reference counter
Command pulse
Feedback
pulse
Detection
unit
To
velocity
control
-
+
Set CMR and DMR so that the pulse weight of + input (command
from the CNC) into the error counter matches the pulse weight of
-input (feedback from the position detector).
[Least command increment]/CMR=[Detection unit]=[Feedback pulse
unit]/DMR
[Least command increment]: Minimum unit of commands issued from
the CNC to the machine
[Detection unit]: Minimum unit for machine position detection
The unit of feedback pulses varies, depending on the type of detector.
[Feedback pulse unit]=[Amount of travel per rotation of the pulse
coder]/[Number of pulses per rotation of the pulse coder]
As the size of the reference counter, specify the grid interval for the
reference position return in the grid method.
[Size of the reference counter]=[Grid interval]/[Detection unit]
[Grid interval]=[Amount of travel per rotation of the pulse coder]
The setting of a command multiplier is as follows:
(1) When command multiplier is 1 to 1/27
Set value = 1 / command multiplier + 100
Valid data range : 101 to 127
(2) When command multiply is 0.5 to 48
Set value = 2 × command multiplier
Valid data range : 1 to 96
NOTE
If a feedrate exceeding the feedrate found by the
expression below is used, an incorrect travel
amount may result or a servo alarm may be issued.
Be sure to use a feedrate not exceeding the
feedrate found by the following expression:
Fmax[mm/min] = 196602 × 10
4
× least command
increment / CMR