The feedback device port of Argon has “only” 15 pins, just like earlier drive model VSD-E, but tons of more of more capabilities have been squished into it. It has:
- 5V 500 mA output
- 5 differential input lines where 3 of them are bidirectional
- 3 single-ended digital inputs
- 2 differential 1 Vpp analog inputs
- Differential inputs may be used with single ended signals as well
All this makes it possible to support many kinds of feedback devices such as:
- Quadrature encoder with index channel
- SinCos encoder with interpolation factor up to 1000x
- Tachometer
- Resolver (a.k.a. synchro)
- Hall sensors
- Serial encoderes (SSI, BISS etc). Support for example for Austria microsystems low cost magnetic linear & rotary encoders possible.
VSD-E could support only the first of them so I think the progress is quite significant.
Which feedback devices are supported ex-factory and don’t need additional driver written by the user?
Currently fully implemented are quadrature & halls. SinCos and resolver modes are on halfway done but will be finished eventually. Once I get serial encoders, I will also try include them in official FW.
The FW sources will be in Github, so anyone can commit improvements :)
Controlling an SMPM information about the pole’s position is needed for the current control. Usualy the Resolvers and the most other encoders don’t generate a signal for the electrical commutation. But there could be an “offset” stored into the drive’s parameters. It’s just an example solution. There are also other approaches – Hall sensors, ex-factory positioning of the encoder’s zero over one of the motor poles etc.
What is foreseen for the Argon in this direction?
Halls, resolvers and some serial encoders are absolute, so current driven phase align not compulsory at start-up. Offset parameter is a very good idea! I will keep it in mind and think how I can make it easy to setup (some auto-setup is the only way here as randomly shooting some offset values is very frustrating).
This servo driver could drive serial encoders like serial encoders found on Yaskawa or Mitsubishi etc.. servomotors ?
For exemple the UTSIH-B17CC encoder…
I could not find protocol specifications for UTSIH-B17CC encoder but it is likely that hardware could support it because almost every serial encoder has just some sort of SPI data bus.
So it’s practically just matter of firmware if the support will be realized. Without knowing its protocol its impossible to say whether it will work or not. However, if protocol is known, then either we or anyone else may implement the encoder support to the open source FW.