yalang yl620 VFD rs485/modbus communicaiton

Just a quick addendum for anyone setting up an RS485 Modbus PC->VFD link: I found it necessary to add a 120 Ohm resistor to both ends of my screened twisted pair cable. Without the resistors, LinuxCNC doesn't always see the RS485 connection and throws a error. As soon as I added the resistors, the connection was stable.
More here: www.analog.com/en/technical-articles/rs4...axim-integrated.html

hey david can you post your files that you used to get this working as ive done a fresh config with stepconf using classicladder but the pyvcp panel doesnt respond, the gauge doesnt move and the spindle at speed and rs485 indicator are red so i dont know what the problem is but i get a stable modbus connection to the vfd and can run and stop the spindle with the plus and minus buttons in axis gui,

yalang and huanyang are not the same VFD

I have enter this setup but there is communication problem.
In thw VFD display seems F399.9 message, and the CB1241 in S7 1200 blink TX and RX leds slow
What can I do please?