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5-15 Overrun Protection
Operating Functions
5
5-15 Overrun Protection
Function
The Servomotor can be stopped with an alarm for an overrun limit error (alarm code 34) if the
Servomotor exceeds the allowable operating range set in the Overrun Limit Setting (Pn026) with
respect to the position command input.
This can be used to prevent impact on the edges of the machine because of Servomotor
oscillation.
Parameters Requiring Settings
Operating Conditions
The overrun limit will operate under the following conditions.
Conditions for Clearing the Position Command Input Range
The position command input range will be cleared to zero under the following conditions.
The power supply is turned ON.
The position deviation is cleared. (The deviation counter clearing is enabled and drive prohibit
input is enabled by setting the Stop Selection for Drive Prohibition Input (Pn066) to 2.)
Normal mode autotuning starts or ends.
The position data is initialized (such as during component setup request, origin return, coordinate
system setup, or adjustment commands)
Parameter
No.
Parameter name Explanation
Refer-
ence
page
Pn026 Overrun Limit Setting
Sets the Servomotor’s allowable operating range for
the position command input range.
(Setting range: 0 to 100 rotations)
An overrun limit error (alarm code 34) will occur if the
set value is exceeded.
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Conditions under which the overrun limit will operate
Operating mode Position Control Mode is used.
Others
1. The servo is ON.
2. The Overrun Limit Setting (Pn026) is not 0.
3. The allowable operating range for both forward and reverse is within 2,147,483,647 after the
position command input range is cleared to zero.
If the condition 1 above is not met, the Overrun Limit Setting will be disabled until the conditions
for clearing the position command input range are satisfied, as described below.
If the conditions 1 and 2 above are not met, the position command input range will be cleared
to zero.
Note this function is not intended to protect against abnormal position
commands.
When the overrun limit error occurs, the Servomotor is decelerated and
stopped according to the Stop Selection for Alarm Generation (Pn068).
Set Pn026 to a range taking into account the deceleration operation.
Otherwise, the loads may hit and cause damage to the machine ends
during deceleration.
Precautions
for Correct Use