
4. SERVO FUNCTION DETAILS B-65150E/04
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(5) VCMD signal
When the feed-forward function is not used, the VCMD signal conveys
a velocity command.
With this signal, it is possible to measure very slight vibration in the
motor and its motion irregularity.
When the feed-forward function is used, the VCMD signal represents a
positional deviation rather than a velocity command. So the signal can
be used to measure vibration in the motor and irregularity in the feed
distance of the tool driven by the motor.
The signal conversion type for the VCMD signal can be switched using
parameters.
This switching is used, if the signal waveform is hard to observe
because of the VCMD signal being reciprocating within ±5 V.
#7 #6 #5 #4 #3 #2 #1 #0
1956 8X12 VCM2 VCM1
2012 1012
Parameters for rotational motor
VCM2 VCM1 Specified rotation speed/5 V
0 0 0.9155 rpm
0 1 14 rpm
1 0 234 rpm
1 1 3750 rpm
Parameters for linear motor
VCM2 VCM1 Specified velocity/5 V
0 0 0.075 m/min
0 1 1.2 m/min
1 0 19.2 m/min
1 1 307.2 m/min
Using an oscilloscope to see the movement of the entire signal in DC
mode, then its magnified image in AC mode enables you to check very
slight vibration in the motor and its motion irregularity.
DC mode
AC mode
Enlarged
Fig. 4.19 (d) Waveform of the VCMD signal