
4. SERVO FUNCTION DETAILS B-65150E/04
− 238 −
(b) Notes on using PMC velocity control
When PMC velocity control is used, and a very small value is set
as the number of velocity pulses (PULCO), the difference
between a specified velocity and actual velocity may become
large. In such a case, modify the settings as described below.
#7 #6 #5 #4 #3 #2 #1 #0
1741
−
SPVCMD
2201
−
SPVCMD (#7) The setting of the number of velocity pulses when the conversion
coefficient (SBPDNL) is not used is:
0: Disabled
1: Enabled ← To be set
1876
−
Number of velocity pulses (PULCO)
2023
−
When a Serial A or αA1000 built-in pulse coder is used, set 8,192.
Example of setting
Make the following modifications when PMC velocity
control is used in the example of (a) of (3) above:
No. 1741#4 = 1
No. 1876 = 8,192
(4) Using a smaller-current amplifier
By using a smaller-current amplifier instead of the normal amplifier,
the current detection resolution can be increased, hence smoother
control can be achieved.
Note, however, that the maximum torque of the motor becomes smaller
as a result of reducing the maximum current.
To enable this modification, set the following parameter:
1733
−
Detection resistance conversion coefficient (SBAMPL)
2122
−
Set the following:
Maximum current of amplifier that is actually used
× 100
Maximum current of amplifier that is usually used
Example of setting
When the α3/3000 (normally driven by a 40-A
amplifier) is driven using the amplifier designed for
the α2/2000 (12 A maximum)
No. 1733 = (12/40) × 100 = 30