You have me confused, but let me try something.
Even though your machine is a brushless one, the 4th axis drive should be brush and brushless. Check the number on it and see. There is also a label on the control panel door stating what the 4th drive is. If it came with a 4th axis drive it would have been brush/brushless. Either way you should not be having to use any converter or what you called and inductor for the table. Drive should have a 17 pin cable and should just plug into the cabinet. The machine in "Settings" should be changed to what ever unit you have, a 210 in you instance. There is a table of setting in "Parameters" that may need to be changed, but worry about that later.
So check your drive.