MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D - Manual (Page 493)

12 - 17
MELSEC-Q
12 CONTROL SUB FUNCTIONS
[3] Precautions during control
It is recommended that the "movement amount per pulse (A)" be set to a value
close to "1" for the following reasons. The "movement amount per pulse" of "1"
means the minimum value in each " Pr.1 Unit setting". (0.1 [
µ
m] for the unit
[mm])
(1) If the setting of the movement amount per pulse is less than 1, the
command frequency may increase, causing the actual speed to exceed the
speed limit value (" Pr.8 Speed limit value", " Pr.31 JOG speed limit
value") and the servomotor to result in overspeed.
(2) If the setting of the movement amount per pulse is less than 1, the
mechanical system may oscillate. If the movement amount per pulse
becomes less than 1, use the electronic gear function of the drive unit and
make setting so that the movement amount per pulse is 1 or greater.
(3) Set the movement amount per pulse so that the pulse output frequency to
the drive unit becomes a value of 200kpps/1Mpps or less.
If a value is set so that the pulse output frequency to the drive unit exceeds
200kpps/1Mpps , the QD75 may not operate correctly.
They indicate the values of QD75P / QD75D.
(4) When using a hundred-thirty thousand pulses encoder, use the electronic
gear function of a drive unit.
(5) Use the electronic gear function among the range indicated below.
Movement amount per pulse (A) >
1
500
REMARK
In the QD75, the general term for the functions in items [1] to [3] above is defined as
the "electronic gear function". Refer to the User's Manual for the servomotor for the
definition of the "electronic gear" on the servomotor side.