Corrected from:
i700 servo inverter, V1: V01.11.12.12374
i700 servo inverter, V2: V02.11.12.12375
Response of the new version:
The internal calculations are now made with 64-bit variables, so that the described inaccuracies no longer occur.
Even with high speeds and high position resolutions, the TP positions are identified correctly now.
What happens?
Touch-probe function: Under certain conditions, there are large deviations in the detected TP position.
The maloperation occurs sporadically since the deviation depends on the relationship between the time of the TP event and the sampling cycle in the device.
If the time between the TP event and the last sampling of the actual position is too long, there may be an overflow of the 32-bit variables in the calculations for determining the TP position.
When does this behaviour occur?
The behaviour occurs under the following conditions:
the selected position resolution (0x608F:1 or 0x688F:1) is much higher than the Lenze setting AND
the TP is detected at high speed AND
there is a big interval between the TP event and the last sampling of the actual position.
Under the above conditions, there may appear large intermediate values in the calculations for determining the TP position as a result of which the 32-bit display area may be exceeded. As a consequence, there will be large deviations in the determined TP position. The described behaviour only occurs with speeds higher than the following speeds:
16 bit (65,536 incPos/rev) -> from 240,000 rpm (not reached in practical operation)
18 bit (262,144 incPos/rev) -> from 60,000 rpm (not reached in practical operation)
20 bit (1,048,576 incPos/rev) -> from 15,000 rpm (not reached in practical operation)
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22 bit (4,194,304 incPos/rev) -> from 3,750 rpm
24 bit (16,777,216 incPos/rev) -> from 937 rpm
26 bit (67,108,864 incPos/rev) -> from 234 rpm
28 bit (268,435,456 incPos/rev) -> from 58 rpm
30 bit (1,073,741,824 incPos/rev) -> from 15 rpm
Condition: (speed * position resolution) / 4000 > 65536 | Units: ( [rev/s] * [incPos/rev] ) / [task cycle/s] > [incPos/rev]
Which products are affected?i700 servo inverter, V1
i700 servo inverter, V2
Short-term measures:
Only use the touch-probe function at low speeds in the case of operation with increased position resolutions.
Evaluation/recommendations:
Experience has shown that in most applications, the default-set position resolution (16 bit) is not changed in practical operation.
The described behaviour is not relevant for these applications.
