8.3 Precautions to Ensure Safe Tuning
8.3.1 Overtravel Settings
8-8
8.3
Precautions to Ensure Safe Tuning
Perform the following settings in a way that is suitable for tuning.
8.3.1
Overtravel Settings
Overtravel settings are made to force the Servomotor to stop for a signal input from a limit
switch when a moving part of the machine exceeds the safe movement range.
Refer to the following section for details.
5.10 Overtravel and Related Settings
8.3.2
Torque Limit Settings
You can limit the torque that is output by the Servomotor based on calculations of the torque
required for machine operation. You can use torque limits to reduce the amount of shock
applied to the machine when problems occur, such as collisions or interference. If the torque
limit is lower than the torque that is required for operation, overshooting or vibration may occur.
Refer to the following section for details.
8.3.3
Setting the Position Deviation Overflow Alarm Level
The position deviation overflow alarm is a protective function that is enabled when the SERVO-
PACK is used in position control.
If the alarm level is set to a suitable value, the SERVOPACK will detect excessive position devi-
ation and will stop the Servomotor if the Servomotor operation does not agree with the refer-
ence.
The position deviation is the difference between the position reference value and the actual
position.
You can calculate the position deviation from the position loop gain (Pn102) and the motor
speed with the following formula.
•
Rotary Servomotors
•
Linear Servomotors
CAUTION
Observe the following precautions when you perform tuning.
•
Do not touch the rotating parts of the motor when the servo is ON.
•
Before starting the Servomotor, make sure that an emergency stop can be performed at any
time.
•
Make sure that trial operation has been successfully performed without any problems.
•
Provide an appropriate stopping device on the machine to ensure safety.
×
60
Pn102 [0.1/s]/10
*2, *3
×
Denominator
Numerator
Encoder resolution
*1
Motor speed [min
-1
]
Position deviation [reference units] =
Pn102 [0.1/s]/10
*2, *3
Denominator
Numerator
Linear encoder pitch [
m]/1,000
Resolution
Motor speed [mm/s]
Position deviation [reference units] =