bdring
bdring
The 6x wiki page has an example rs485 config. http://wiki.fluidnc.com/en/hardware/official/6x_CNC_Controller#rs485
" if I use uart1 I have an error" What is the error? If the error is in the startup messages, please paste those in a reply.
The 6x wiki page mentions using LEDs to help debug the rs485. Tell what happened?
As the wiki says...If LED 14 and **LED15** are blinking the controller is talking to the VFD, but the VFD is not responding. There are a lot of registers that...
Have you seen this? It is on the wiki. 
What type of switches are you using? Use FluidTerm to do what Mitch suggested and send $H.
Mitch just wrote a new wiki page with a flow chart to help with that. Give it a try. http://wiki.fluidnc.com/en/support/setup/motion
http://wiki.fluidnc.com/en/support/faq#motor-moves-erratically
What do you have the Vcc set for? https://github.com/bdring/6-Pack_CNC_Controller/wiki/Stepper-Jumper-Motor-Setup#stepper-jumper-motor-setup