User`s manual

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9
(2) Electronic gear 2
M2 coefficient (encoder value)
This value is the number of pulses that are returned from the encoder (PG) when the shaft that
drives the table, for example, rotates one turn.
D2 coefficient (encoder value)
This value sets the travel distance when the shaft that drive the table, for example, turns one
rotation.
Determine any unit (µ m, mm, cm, m, degree, inch, etc.) as desired.
Normally, set the same value as the instruction value D1 coefficient.
Setup method
Set the number of required pulses from the encoder to the encoder M value (parameter 2 address
B+0040 to 0043) when the drive shaft rotates one turn. The equation for calculating the M value is
as follows as the feedback value of this module is captured at a factor of four at all times.
M2 coefficient = encoder (PG) pulse count/rotation × gear reduction ratio × multiplication
(fixed to "4")
where,
encoder pulse count/rotation: Number of pulses output by PG when encoder (PG) is
rotated one turn
gear reduction ratio: gear reduction ratio of gear
multiplication: 4 (fixed to "4")
For the D2 value, set the same value as the instruction D1 value. Though the minimum unit for the
feedback value can be changed, compensation using the feedback value or comparison and other
functions cannot be used at this time.
Setting example
The instruction value M2 value becomes 1200 when the encoder (PG) outputs 30 pulses per
rotation, and the gear ratio between the motor and shaft is 10:1 (shaft rotates one turn for every ten
motor rotations).
M=30×10/1×4=1200
Also, the instruction value D2 value becomes 30 when the minimum unit to be managed is set to
0.1 mm assuming that a single rotation of the shaft causes 3 mm of travel. (unit: mm × 10
-1
, same
as instruction value)
Accordingly, the relationship becomes M2/D2=40 214, and no problems are posed within the
restrictions of electronic gear 2.