Mitsubishi Electric RD77MS2 User Manual page 418

Trapezoidal acceleration/deceleration (S-curve ratio is 0%)
V
[Pr.8] Speed limit value
[Da.8] Command speed
[Pr.7] Bias speed at start
S-curve acceleration/deceleration (S-curve ratio is other than 0%)
V
[Pr.8] Speed limit value
[Da.8] Command speed
[Pr.7] Bias speed at start
For the 2-axis or more interpolation control, the bias speed at start is applied by the setting of "[Pr.20]
Interpolation speed designation method".
• "0: Composite speed": Bias speed at start set to the reference axis is applied to the composite command
speed.
• "1: Reference axis speed": Bias speed at start is applied to the reference axis.
■Precautionary notes
• "[Pr.7] Bias speed at start" is valid regardless of motor type. Set "0" when using the motor other than the stepping motor.
Otherwise, it may cause vibration or impact even though an error does not occur.
• Set "[Pr.7] Bias speed at start" according to the specification of stepping motor driver. If the setting is outside the range, it
may cause the following troubles by rapid speed change or overload.
• Stepping motor steps out.
• An error occurs in the stepping motor driver.
• In synchronous control, when "[Pr.7] Bias speed at start" is set to the servo input axis, the bias speed at start is applied to
the servo input axis. Note that the unexpected operation might be generated to the output axis.
• Set "[Pr.7] Bias speed at start" within the following range.
"[Pr.8] Speed limit value"  "[Pr.46] Home position return speed"  "[Pr.47] Creep speed"  "[Pr.7] Bias speed at start"
• If the data ("[Da.8] Command speed" of positioning data, "[Da.8] Command speed" of next point for continuous path control,
or "[Cd.14] New speed value" for speed change function) is less than "[Pr.7] Bias speed at start", the warning "Below bias
speed" (warning code: 0908H) will occur and it will operate at "[Pr.7] Bias speed at start".
• When using S-curve acceleration/deceleration processing and bias speed at start together, S-curve acceleration/
deceleration processing is carried out based on the acceleration/deceleration time set by user, "[Pr.8] Speed limit value"
and "[Pr.35] S-curve ratio" (1 to 100%) in the section of acceleration/deceleration from bias speed at start to command
speed.
12 DATA USED FOR POSITIONING CONTROL
416
12.3 Basic Setting
Actual
acceleration time
Acceleration time
[Pr.9] Acceleration time 0
[Pr.25] Acceleration time 1
[Pr.26] Acceleration time 2
[Pr.27] Acceleration time 3
Actual
acceleration time
Acceleration time
[Pr.9] Acceleration time 0
[Pr.25] Acceleration time 1
[Pr.26] Acceleration time 2
[Pr.27] Acceleration time 3
t
Actual
deceleration time
Deceleration time
[Pr.10] Deceleration time 0
[Pr.28] Deceleration time 1
[Pr.29] Deceleration time 2
[Pr.30] Deceleration time 3
t
Actual
deceleration time
Deceleration time
[Pr.10] Deceleration time 0
[Pr.28] Deceleration time 1
[Pr.29] Deceleration time 2
[Pr.30] Deceleration time 3