What is the protocol used for the Panasonic incremental encoder?

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Discussion Overview

The discussion revolves around identifying the communication protocol used by a Panasonic incremental encoder integrated with a servo motor. Participants explore the challenges of reverse engineering the encoder's serial output for motor control applications, considering both the learning aspect and practical project requirements.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks to understand the protocol used by the Panasonic encoder to facilitate motor control learning, expressing uncertainty about the difficulty of this task.
  • Another participant suggests that reverse engineering the protocol is feasible but can vary significantly in time commitment, depending on complexity and available resources.
  • Some participants propose starting from scratch with a simpler motor and encoder to avoid constraints imposed by the integrated system.
  • There is mention of the possibility that the encoder uses the SSI protocol or a modern derived system like BISS, but some participants express skepticism about these options based on the encoder's specifications.
  • A participant notes that the encoder reportedly outputs a 50 Hz signal regardless of motor movement, raising questions about the expected behavior of the encoder's output.
  • One participant considers the idea that the protocol might simply be RS485, based on their findings while testing the encoder outputs.

Areas of Agreement / Disagreement

Participants express a range of views on the feasibility of reverse engineering the encoder protocol, with some supporting the idea while others suggest alternative approaches. There is no consensus on the specific protocol used by the encoder, and uncertainty remains regarding the expected output behavior.

Contextual Notes

Participants mention various protocols (SSI, BISS, RS485) and their characteristics, but there is no definitive conclusion about which protocol applies to the Panasonic encoder. The discussion includes unresolved questions about the encoder's output signal and its implications for motor control.

Who May Find This Useful

This discussion may be of interest to individuals involved in motor control projects, those learning about encoder technologies, and participants exploring reverse engineering techniques in the context of embedded systems.

Cdz
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I have a Panasonic servo motor( model no.MSME 102GCGM), this motor comes with an encoder installed and a drive.
I am learning motor control, so i need to do the drive myself with dSPACE system and to do that I need the encoder signal as feedback, however the encoder output signal is not ABZ phase signal, rather it uses serial transmission which the Panasonic drive recognizes but the company would not share the protocol used.

To do this, the first thing, I need to know that protocol that is used for this encoder.

Second, after I know the protocol, I need to decode the information so that I can use it for motor control learning.

Am I right? It seems difficult. Anyone have some experience?
Or should I just buy another encoder with ABZ phase output?
 
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Really depends on how much time you have available. Reverse Engineering a protocol is doable but not always easy. With the right equipment it may take only a couple days. But I've seen projects where it takes months in complex cases. If you want to learn and you have the time, you can learn a lot by Reverse Engineering, even learn how to think more logically! So if you have the freedom to spend a week or so, give it a try. You may still end up replacing the encoder though.
 
If this is a learning exercise then why be constrained by another complete integrated system.
Start from scratch with a lower power motor and the encoder of your choice. Keep it simple.
 
Baluncore said:
If this is a learning exercise then why be constrained by another complete integrated system.
Start from scratch with a lower power motor and the encoder of your choice. Keep it simple.
No it's not exactly just a learning exercise. For me, maybe it is, but for my professor it's not. It's a project and I do the basics to make sure the platform works and there will be more advanced work following.
But l like your idea, keep it simple. Neat.
 
Tom.G said:
Really depends on how much time you have available. Reverse Engineering a protocol is doable but not always easy. With the right equipment it may take only a couple days. But I've seen projects where it takes months in complex cases. If you want to learn and you have the time, you can learn a lot by Reverse Engineering, even learn how to think more logically! So if you have the freedom to spend a week or so, give it a try. You may still end up replacing the encoder though.

I think Reverse Engineering is cool. I will try it and buy another encoder just in case.
Wish I make it :smile:
Thank you.
 
There is a reasonable chance that it uses SSI .

If not then it will likely be one of the more modern derived systems such as BISS[/PLAIN]

In any case reading about SSI and BISS will tell you how these types of system work in principle .
 
Last edited by a moderator:
Nidum said:
There is a reasonable chance that it uses SSI .

If not then it will likely be one of the more modern derived systems such as BISS[/PLAIN]

In any case reading about SSI and BISS will tell you how these types of system work in principle .

I read that it is a 20bit incremental encoder and it has only two wires for transmitting signals named as $$PS \enspace\overline {PS}$$ and the manual says serial signal transmission.
I read on Wikipedia that both SSI and BISS have clock signal, so they are not what I am looking for.
So it may be something simpler.
I searched online and there is one guy said the protocol is just RS485. So I tried manually rotating the PM motor and checked the differential outputs of the encoder to look for the Baud rate of transmission.All that I get is a 50 Hz signal,whether I turn the motor or not.
I am supposed to get different outputs when I turn or don't turn the motor, right?
But it's the same. Any suggestions?
 
Last edited by a moderator:

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