Raghav Posted January 16, 2017 Share Posted January 16, 2017 We have 2 PMAC commutated Linear motor with high resolution encoders. The current resolution is 5nm and Motor Scale is 200,000. We have difficulty in increasing the resolution to 2nm as the encoder can be set to 1.22nm. The linear scale is a 20 um grating and the resolution mentioned is a interpolated one. Since we need to perform the commutation on PMAC, the counts exceeds 32M. How can we perform the improvement? Will Encoder Conversion Table help? Thanks in advance. Regards, Raghav Link to comment Share on other sites More sharing options...
JeffLowe Posted January 16, 2017 Share Posted January 16, 2017 We have 2 PMAC commutated Linear motor with high resolution encoders. The current resolution is 5nm and Motor Scale is 200,000. We have difficulty in increasing the resolution to 2nm as the encoder can be set to 1.22nm. The linear scale is a 20 um grating and the resolution mentioned is a interpolated one. Since we need to perform the commutation on PMAC, the counts exceeds 32M. How can we perform the improvement? Will Encoder Conversion Table help? Thanks in advance. Regards, Raghav An additional encoder table entry can be created to only use some subset of the upper bits to reduce the resolution to one that will not exceed the limit. Link to comment Share on other sites More sharing options...
Raghav Posted January 17, 2017 Author Share Posted January 17, 2017 We have 2 PMAC commutated Linear motor with high resolution encoders. The current resolution is 5nm and Motor Scale is 200,000. We have difficulty in increasing the resolution to 2nm as the encoder can be set to 1.22nm. The linear scale is a 20 um grating and the resolution mentioned is a interpolated one. Since we need to perform the commutation on PMAC, the counts exceeds 32M. How can we perform the improvement? Will Encoder Conversion Table help? Thanks in advance. Regards, Raghav An additional encoder table entry can be created to only use some subset of the upper bits to reduce the resolution to one that will not exceed the limit. Hi Jeff, Can you explain a bit more in detail? Regards, Raghav Link to comment Share on other sites More sharing options...
steve.milici Posted January 17, 2017 Share Posted January 17, 2017 We have 2 PMAC commutated Linear motor with high resolution encoders. The current resolution is 5nm and Motor Scale is 200,000. We have difficulty in increasing the resolution to 2nm as the encoder can be set to 1.22nm. The linear scale is a 20 um grating and the resolution mentioned is a interpolated one. Since we need to perform the commutation on PMAC, the counts exceeds 32M. How can we perform the improvement? Will Encoder Conversion Table help? Thanks in advance. Regards, Raghav An additional encoder table entry can be created to only use some subset of the upper bits to reduce the resolution to one that will not exceed the limit. Hi Jeff, Can you explain a bit more in detail? Regards, Raghav I have attached an application note describing the alternative methods.Circumventing the Limit on Ixx71 Commutation Cycle Size.pdf Link to comment Share on other sites More sharing options...
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