Peter,

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I don’t know where you got the idea that either the G1 or G2 can use the index marker on the motor encoder wheels.

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Pin 2 of the encoders isn’t connected to anything and you need fair number of changes to exploit the index marker signals:

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1. An extra wire from the motors to the controller for the index signal
2. Encoders that actually do output the index signal
3. Motor PCBs that routed this signal to a 7 pin connector
4. Changes to the PIC software that manages the motor to make use of the index signals
5. Changes to the protocol used for the SPI messages between the PIC and the ARM
6. Changes to the ARM code to make use of the index information.

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The early servo motors (and maybe also the Maxon motors) use HEDS-9100 encoders which don’t have index marker detection/output on pin 2 (you need HEDS-9140 for that).

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While the High-Torque motors now use US Digital encoders they probably don’t use the variant with the index marker output as that would cost more and there’s no way to use it.

David

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