Corrected from:
- i700 servo inverter V01.06.03.9953
Response of the new version:
The described behaviour no longer occurs.
What happens?The synchronous linear motor cannot generate any torque or, in the worst case, may even move in an uncontrolled way.
When does the problem occur?
The problem occurs when using a linear TTK70/TTK50 Hiperface SinCos absolute value encoder together with a synchronous linear motor.
After mains switching or an error in the feedback system, the commutation angle is not calculated correctly within the motor control of the i700.
The absolute position transferred from the i700 to the controller application is, however, correct. The faulty commutation angle can only be recognised in the objects 0x2DDE (and 0x35DE). Furthermore, in the object 0x2C42:3 (0x3442:3) "Encoder: Angle drift - Actual angle error", a value significantly deviating from 0 degrees is indicated.
As a result of an incorrect angular pole position determination, it may happen that for synchronous motors (SM), and, accordingly, also for synchronous linear motors, either no torque can be generated, or a torque in opposite direction may be generated so that the motor will "run away" due to a positive feedback in the control loop.
Which products are affected?
- i700 servo inverter ≤ V01.05.06.9665
Short-term measures/recommendations:
Identify the pole position every time after mains switching and after every feedback system error.
Evaluation:
Since the drive may move in an uncontrolled way, it is absolutely necessary to use the later i700 firmware version!
