
4. SERVO FUNCTION DETAILS B-65150E/04
− 236 −
In this case, the current loop parameter must be modified. With the
Series 9081, required conversions can be made only by setting a bit
parameter.
For an explanation of how to make this setting, see (5) in this section.
Example)
When the supply voltage for driving the motor is changed from
200 V to 60 V (In this case, an amplifier modification is also
required.)
4 When the position detection unit of the laser or
scale is 0.001 µm, and the number of position
pulses per motor revolution exceeds 1,000,000
(resolution of serial pulse coder A)
In this case, the number of position feedback pulses becomes greater
than the number of velocity feedback pulses (1,000,000 pulses for
αA1000 or serial pulse coder A), so that stable positioning cannot be
performed. In such a system, a separate velocity detector must also be
used as described in (6) of this section.
Example)
When the amount of travel per motor revolution is 5 mm, and
0.001-µm position detection is performed (when the number of
position pulses per motor revolution is 5,000,000)
(2) Series and editions of applicable servo software
Series 9081/C(03) and subsequent editions (Series 15-B,16-C,18-C)
(3) Using a separate position detector with 130,000 pulses per motor
revolution
(a) In this case, a servo parameter causes an overflow in the digital
servo system, so that the number of velocity pulses and the
number of position pulses must be set as follows:
1732
−
Conversion coefficient for the number of feedback pulses (SBPDNL)
2121
−
The value specified in this parameter is used to divide the number of
velocity pulses and the number of position pulses to produce a value
not exceeding 32,767. For this parameter, set as small a value as
possible.
[Typical setting] 100 or 1,000
1876
−
Number of velocity pulses (PULCO)
2023
−
When a Serial A or αA1000 built-in pulse coder is used, set
SBPDNL
8,192
.