[FluidNC Issue#1512] Problem: AC servo motor

#1 – bdring 于 2025-06-18

We need datasheets on your parts and a schematic of how you are hooking everything up.

The config file and messages are applicable. Please edit your initial post to add them.

If you are trying to use RS485, we do not support that.

http://wiki.fluidnc.com/en/hardware/motors/servos

#2 – rewwer56 于 2025-06-18

What type of communication between the two controllers do you suggest?

#3 – bdring 于 2025-06-18

!Image

#4 – rewwer56 于 2025-06-18

Thanks

#5 – MitchBradley 于 2025-06-18

I just want to clarify something. The thing about supporting only step/direction control applies to axis motion, not to spindle control. For spindles, we support the following control methods:
* Manual operation
* On/off via digital signals, relays or solid state relays
* Direction via digital signals or relays
* Speed control via 0-10V analog or digital PWM
* RS485 communication using the Modbus protocol

As Bart said, we would need more information about the controller for your servo motor to know if it is compatible with the above methods.

#6 – MitchBradley 于 2025-06-18

Many of the AC Servo controllers that I looked at support Modbus RTU communication, for use with, for example, PLCs. FluidNC supports Modbus RTU. We have “out-of-the-box” support for the specific Modbus messages that are used by a few particular VFD models, but it is unlikely that any given AC Servo controller uses exactly the same messages. We have a “generic VFD” module that can be configured with custom message formats. It is possible that, if you can find documentation about the message details for your particular controller, the generic VFD module would work with it.

#7 – rewwer56 于 2025-06-19

Good day,

I’ve this servo-set:
https://www.omc-stepperonline.com/a6-series-750w-rs485-ac-servo-motor-kit-3000rpm-2-39nm-17-bit-absolute-encoder-ip67-a6-rs750h2a1-m17

#8 – MitchBradley 于 2025-06-19

It looks like it should be possible to control that with RS485, but the download link for the manual is broken so I can’t be sure. When I tried to download the manual for the servo drive, I got “ERROR 403: Forbidden.”

#9 – rewwer56 于 2025-06-19

#10 – MitchBradley 于 2025-06-20