Corrected from:
- Inverter Drives 8400 TopLine V15.01.00
Response of the new version:
There is only an offset of a few negligible increments.
Which products are affected?
Inverter Drive 8400 TopLine up to firmware version 12.01.00.00
What happens?
The edges of the Z-track at different speeds are not, as expected, positioned incrementally in the same position within an encoder revolution. At n=3000rpm, the Z-pulse is delayed by approximately 0.1 revolutions.
In the case of synchronisation via zero pulse in electrical shaft applications, speed-dependent deviations can be observed.
When does the problem occur?
If the zero pulse of an encoder for which an exact position reference is required is evaluated (encoder Tp).
Diagnostics options?
The position of the Z-pulse can be diagnosed via the outputs bTpEncoderReceived and dnTpEncoderPosition_p at the LS_TouchProbe system block.
Short-term measures/recommendations?
The signal delay can be compensated via the setting C2811/8=125µs.
Evaluation:
The expected speed-independent accuracy of the encoder touch probe for synchronisation functions of an electrical shaft application is not given. During homing to the zero pulse, typically a low speed is used, so that only slight errors will result here.
The parameterisable compensation provides simple remedy.
