6 FUNCTIONAL SAFETY
6.4 Safety sub-function
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Servo motor with functional safety
By using a servo motor with functional safety, various speed monitoring functions and position monitoring functions can be
realized without using external encoders to duplicate encoders.
When using a servo motor with functional safety, set [Pr. PSA02.1 Position/Speed monitor setting] to "1". When not using a
servo motor with functional safety, set this parameter to a value other than "1". Refer to the following for details.
Page 342 Achievable safety level
Position feedback fixing diagnosis function
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Outline
The position feedback fixing diagnosis function sets the STO state when the position data from the encoder is fixed and [AL.
52A Position feedback error (safety sub-function)] occurs.
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Operation outline
The position feedback fixing diagnosis function is enabled when the safety sub-function is enabled and the status is other than
the STO state. If there is no change in position feedback for the time set in [Pr. PSA22 Position feedback error detection time],
[AL. 52A Position feedback error (safety sub-function)] occurs and the STO function is activated.
[Pr. PSA22]
ALM (malfunction)
ON (disabled)
OFF (enabled)
STOS (STO output)
OFF (shut-off)
Stop
STO state
Servo motor position
Rotation
Position (P)
Position change: 0 pulse
ON (disabled)