Mitsubishi Electric MELSEC iQ-F Series FX5 User Manual page 380

[Pr.7] Bias speed at start
Set Minimum speed at start for Bias speed at start. Set Bias speed at start to allow the motor to start smoothly especially
when a stepping motor is used. (A stepping motor does not start smoothly if a low rotation speed is instructed at the start.)
■Bias speed at start is "0"
Speed
The specified Bias speed at start will be valid during the following operations:
• Positioning operation
• OPR
• JOG operation
Set a value equal to or less than the value set in [Pr.8] Speed limit value.
■Buffer memory address
The following table shows the buffer memory address of this area.
Buffer memory name
[Pr.7] Bias speed at start
■Setting range
The setting range depends on the setting of [Pr.1] Unit setting.
Setting of [Pr.1] Unit setting
0: mm
1: inch
2: degree
3: pulse
*1 When this buffer memory area is set with programs, a calculation is performed in the positioning module to convert a setting value to the
value in each unit. For setting this buffer memory area, take the value after the unit conversion into consideration.
■Default value
The default value is 0 for all the axes.
■Precautions for using a stepping motor
• For the system that uses a stepping motor, executing the S-curve acceleration/deceleration may cause step out. Before
using the S-curve acceleration/deceleration, check that step out does not occur.
• In the system that uses a stepping motor, the circular interpolation control cannot be performed. Although setting the bias
speed at start is required by the characteristics of the stepping motor, the setting of the bias speed at start is disabled for
circular interpolation control. Use a servomotor for both axes when circular interpolation control is performed.
17 DATA USED FOR POSITIONING CONTROL
378
17.3 Basic Setting
■Bias speed at start is "Other than 0"
Command speed
t
Axis 1
6
7
Setting value via GX Works3
0 to 20000000.00 (mm/min)
0 to 2000000.000 (inch/min)
0 to 3000000.000 (degree/min)
0 to 5000000 (pulse/s)
Speed
Acceleration starts after the startup bias
speed is reached
Axis 2
156
157
Setting value with programs
0 to 2000000000 (×10
0 to 2000000000 (×10
0 to 3000000000 (×10
0 to 5000000 (pulse/s)
Command speed
t
*1
-2
mm/min)
-3
inch/min)
-3
degree/min)