Finally I did it
I made a factory reset on the VFD and started over the settings.
What I did with Sako SKI-780:
- Set the PP-01 to 01 manual on the VFD control panel (01 = reset factory settings except motor parameters)
- I used the default 9600 baudrate.
- Set the command source to RS485 with serial console app (01 06 F0 02 00 02 9A CB).
- Set the main frequency source to RS485 with serial console app (01 06 F0 03 00 09 8A CC).
- Changed the Modbus protocol to 31, standard Modbus communication, through RS485 with serial console app (01 06 FD 05 00 1F).
- Changed the Modbus data format to 8,N,1 (value 3) through RS485 with serial console app (01 06 FD 01 00 03).
What is the most interesting, if I now debug LinuxCNC in terminal, I can see that the CRC Low and high bits are still in reverse order, but works. For example:
Read baudrate
Request: 01 03 FD 00 00 01 B5 A6
Response: 01 03 02 17 75 76 53
Calculated response CRC: 0x5376
Write baudrate
Request: 01 06 FD 00 17 75 76 71
Response: 01 06 FD 00 17 75 76 71
Calculated response CRC: 0x7176
Set spindle speed to 100Hz
Request: 01 06 10 00 09 C4 8A C9
Response: 01 06 10 00 09 C4 8A C9
Calculated response CRC: 0xC98A
So I don't know what was the key parameter for the solution, but now it works, and I hope, next time if someone walks the same way, will end up in less dead ends like me did (I think because of my inattention)
