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[A_Camera]

If it continues to work for me I need another solution for vfd control! Is rs485 to usb twowire system ok?
But that only let's you control speed and not start/stop from system? Or am I mistaken? :D

Yes, you are mistaken. I don't know which VFD you have, but as far as I know, all VFD which allows RS485 control has at least on/off/forward/reverse/speed commands. I control mine via Modbus protocol and even download some monitoring data.

The USB dongle is fine for Modbus but some models are better than others. I have one like this...



...which I don't use because I wanted Ethernet control, so I bought this one:



Both works reliably, and in fact, you can also buy a WIFI version, which I'd probably go for today, if I not already had this wired one.