Instructions On Identifying Inertia - INVT DA180-S2R8SG0 Operation Manual

DA180 series basic AC servo drive

7.1 Instructions on identifying inertia

Inertia can be identified online or offline.
Identifying inertia online
Before selecting online inertia identifying, you must set the parameters P1.00 [Tune inertia online] and
P1.08 [Inertia identifying class].
The online identifying mode is valid when P1.00 and P1.08 are greater than 0. If the following inertia
identifying conditions are met:

The speed is higher than 150 r/min.

The ACC time is greater than 20ms.

The continuous ACC range exceeds 150 r/min.

The ACC is reached within 0.3s (from 0 r/min to 3000 r/min).
The inertia identifying result is automatically updated to P1.01[Inertia ratio 1] and written to the
EEPROM at an interval of 30 minutes.
Identifying inertia offline
Before selecting offline inertia identifying, you must set the parameters P1.05 [Inertia identifying
mode], P1.06 [Max. rotations by inertia identifying], and P1.07 [ACC time for inertia identifying]. You
can enable offline inertia identifying by using the auxiliary function EF-JId on the panel. For details,
see section 5.2.5.5 "Inertia identifying". Offline inertia identifying is not affected by P1.00 [Tune inertia
online] and P1.08 [Inertia identifying class].
Before enabling the auxiliary function EF-JId, set P1.05 based on the motor allowed running mode,
P1.06 based on the motor allowed rotations, and P1.07 based on the mechanical rigidity. Strong
mechanical rigidity allows you to set a small ACC/DEC time constant. P1.05 can be set to 1 indicating
forward rotating or 2 reverse rotating. If P1.06 is set to a greater value while P1.07 is set to a smaller
value, the inertia identifying result is more accurate.
In addition, ensure the settings of P1.05 and P1.06 are compliant with the mechanical structure.
Otherwise, mechanical damage may be caused. During the execution, you can press the Mode key
to terminate.
If the auxiliary function EF-JId is executed successfully, the identifying result is automatically saved to
P1.01 [Inertia ratio 1]. If a fault occurred during the identifying, P1.01 keeps the previous setting. If
fault Er25-7 [Inertia identifying failed] is reported, try to set P1.06 to a greater value or P1.07 to a
smaller value.
If the following occurs onsite:
• Low mechanical rigidity
• Sharp change on load inertia
• Non-linear characteristics such as clearance
• Sudden change on external disturbance
The inertia identifying result accuracy is impacted.
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Commissioning