Problem with Huanyang VFD communication via RS485 in LinuxCNC

deltafox24
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2 years 1 week ago #312780 by deltafox24

Problem with Huanyang VFD communication via RS485 in LinuxCNC was created by deltafox24

Hello everyone!. please help me to customize the inverter under linuxcnc. i've been struggling for 2 weeks. I’m facing an issue with connecting my Huanyang VFD to LinuxCNC via RS485. It works perfectly in Windows, but I’m having trouble in Linux. I’m using an RS485-RS232 converter through the COM port, and despite configuring everything, the spindle does not respond, and the program either hangs or there’s no communication with the VFD.System:

LinuxCNC 2.9.3(Debian 12)
RS485-RS232 converter
Huanyang VFD configured for Modbus RTU
What I’ve done so far:
VFD Settings:
- The following settings are configured on the VFD:
  - PD001 = 2 — control via Modbus.
  - PD002 = 2 — frequency via Modbus.
  - PD163 = 1 — device address.
  - PD164 = 9600 — baud rate.
  - PD165 = 3 — 8 data bits, no parity, 1 stop bit (8N1).
Using

Code:

hy_vfd

: I tried running

Code:

hy_vfd

, but the program hangs when opening the port. Here’s the command:
bash
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Code:

hy_vfd -d /dev/ttyS0 --rate 9600 --parity none --stopbits 1 --target 1 -g

Log output:
bash
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Code:

hy_vfd: device='/dev/ttyS0', baud=9600, bits=8, parity='none', stopbits=1, address=1, debug=1, PID=1586 Opening /dev/ttyS0 at 9600 bauds (none)

The program hangs at the stage of opening the port.
Checking the port via

Code:

minicom

: I connected to the port via

Code:

minicom

:
bash
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Code:

sudo minicom -D /dev/ttyS0

The port settings are 9600 8N1, but in the terminal, commands do not send and there’s no response from the VFD. The port is not occupied:
bash
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Code:

lsof /dev/ttyS0

The output is empty, meaning nothing is occupying the port.
Testing with

Code:

mbpoll

: I also tried using

Code:

mbpoll

to send Modbus messages:
bash
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Code:

mbpoll -a 1 -b 9600 -P none -d 8 -s 1 -t 3 /dev/ttyS0

I get the following error:
objectivec
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Code:

Read input register failed: Connection timed out
What I’ve tried so far:
Double-checked all wiring (Data+ and Data-).
Tried changing the baud rate to 19200, but the result was the same.
Tried different ports, including

Code:

/dev/ttyUSB0

(if using a USB-RS485 converter).
Added my user to the

Code:

dialout

group:
bash
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Code:

sudo usermod -aG dialout $USER
Attempted to reload HAL with

Code:

halrun

and manually load

Code:

hy_vfd

:
bash
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Code:

halrun loadusr -W hy_vfd -d /dev/ttyS0 --rate 9600 --parity none --stopbits 1 --target 1 -g
Questions:
What else can I do to debug the connection with the VFD?
Could my RS485-RS232 converter be the problem? Could you recommend any converters that are known to work well with Linux?
Are there any special settings for serial ports or Modbus in LinuxCNC that might be causing this issue?
Thanks for your help! I’d appreciate any advice or recommendations.Additional Info:
RS485-RS232 converter: Works perfectly in Windows Mach3.
Linux: Debian 12 running LinuxCNC.