ACC-53E / ACC-84S and Multiturn Absolute Encoders

[Abhijit]

I want to interface SSI multiturn encoder to ACC-53E/ACC-84S. Multiturn resolution will be 12 bits and single turn resolution will be 17 bits. The encoder output will be in extended SSI format as specified in attachment. Is this possible ? As per my knowledge, currently encoder conversion table does not have a format to allow this.

Technical_Manual_SSI_BiSS_ACURO_en.pdf

[Omron Forums Support]

Abhijit,

 

Based on the description and diagram of the Extended SSI Protocol on page 8/29 of the document you attached, the single-turn data is first transmitted, followed by the multi-turn data, and the position data seems to all be contiguous. The position data appears to all be transmitted before any of the status bits are transmitted. If this is all true (you should double-check it), then ACC-84S can handle the position information. In the Channel-Specific Control Word involved in setting up the ACC-84S in software, you need to specify the exact number of bits of position information to use in order that the PMAC will not mistake any of the status bits for position bits.

 

Below is an image demonstrating an example of how the position information needs to be arranged within the serial encoder data registers on ACC-84S:

 

[Abhijit]

Thank you for the information.

 

Does this apply to brick controller, geo brick drive and geo pmac having appropriate options selections for absolute SSI encoder feedback ?

[Omron Forums Support]

Hello,

 

This also applies to Geo Brick and Brick Controller, as their SSI circuitry is essentially the same as ACC-84S's. However, I am unsure about Geo PMAC. Let me investigate a little and I can post later.

[Omron Forums Support]

It appears that the SSI interface on Geo PMAC is slightly different from these other products you mentioned. The setup method is different and it can only process feedback resolution up to 24 bits. Please refer to pages 48-49 of the Geo PMAC Manual for more details.