6.1 C-S Axis Control
6-5
Additional Functions
If Pn002.3 is 1, the encoder pulse output will change to phase B advanced when the motor is rotated in the for-
ward direction.
If Pn002.3 is 3, the encoder pulse output will change to phase A advanced when the motor is rotated in the for-
ward direction.
6.1.5
External Encoder Sine Wave Pitch (Frequency) Setting
The number of external encoder pitches per motor revolution is set in Pn20A.
A setting example is given below.
If a direct drive connection to the motor is used, 30 mm/0.02 mm = 1,500, so the set value is 1,500.
Note 1. If this results in a fractional number, round off the decimal portion.
2. If the number of external encoder pitches per motor revolution is not an integer, the position loop gain (Kp), feed-
forward, and position reference speed monitor will deviate from the speed loop.
However, this will not affect position accuracy and therefore no position displacement will occur.
The following table lists the related parameters.
6.1.6
Setting Alarm Detection
This section describes the parameters for alarm detection (Pn51B and Pn52A).
(1) Setting the Excessive Error Level between Servomotor and Load Positions
(Pn51B)
This parameter detects the difference between the motor encoder feedback position and the fully-closed loop
external encoder feedback position (i.e., the load position).
If the set value is exceeded, the Motor-load Position Error Overflow Alarm (A.d10) will be output.
Note: If this parameter is set to 0, the Motor-load Position Error Overflow Alarm (A.d10) will not be output.
(2) Setting the Multiplier per One Fully-closed Rotation (Pn52A)
This parameter sets the deviation coefficient between the servomotor and external encoder per servomotor
revolution.
This can protect against overrun due to external encoder malfunction and detect slipping in belt mechanisms.
Specifications
External encoder pitch: 20
μ
m
Ball screw pitch: 30 mm
Speed: 1,600 mm/s
Pn20A
Number of External Scale Pitch
Classification
Setting Range
Setting Unit
Factory Setting
When Enabled
4 to 1,048,576
1 pitch/rev
32,768
After start
Setup
Position
Pn51B
Excessive Error Level between Servomotor
and Load Positions
Classification
Setting Range
Setting Unit
Factory Setting
When Enabled
0 to 1,073,741,824
1 reference unit
1,000
Immediately
Setup
Position
