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On a rotary application with absolute multi-turn feedback, it's possible to run over the feedback unwind. If the machine has a non-binary gear ration (e.g. 3:1), its period is not an integer divisor of the encoder period, allowing the position to not be the same after a power cycle. In other words, it may be shifted by the fraction of the ratio.

BiSS-C is a digital encoder protocol that permits a wide range of possible formats. The AKD supports the most common BiSS-C format, and can only guarantee support for the encoders listed in "Documented BiSS-C Encoders". To determine if a BiSS-C device not listed here is supported by the AKD, follow the steps in "Setting Up an Undocumented BiSS-C Encoder"

Documented BiSS-C Encoders

The following BiSS-C encoders are known to work with an AKD. This list does not include BiSS-B encoders, which function differently.

This application note applies to the AKD Motion Tasking drive in the case where the motor to load is direct drive and the position of the load is always between 0 to 360 degrees. This is typical in rotary dials/indexing tables. Sometimes the objective is to have the zero position to be set in a position different from the zero angle of the motor/feedback. This application describes the steps taken to define a new "zero" position.

On a rotary application with an absolute multi turn feedback it's possible to run over the feedback unwind. If the gear between motor and application is binary nothing happens. If the application has a non binary gear ratio, the position after a restart of the drive may not be same. To readjust this situation the FB1.OFFSET needs to be corrected. On a producing machine it's not usable if, after every power cycle, an electrician has to recheck the position of the axis. For this situation the following auto correction has been implemented in the PLC code.

We offer 2 absolute multiturn feedback options 1) Endat and 2) Biss. I believe that Biss is absolute for 13 bits (2^13 = 8192 turns) and Endat is absolute for 12 bits (2^12 = 4096).

Please confirm and provide any documentation that states this information. This is a typical question customers ask.