I am using a masso controller for a 3 axis cnc machine. The problem with my controller is that it doesn't support any usb distributor. I cannot connect both keyboard, mouse and pen drive at the same time. Seems like it is unable to supply power to these 3 units at the same time. I am using very normal keyboard and mouse that are rated for few watts only, but seems it can't power it up. When i connect keyboard and mouse directly to masso, they work perfectly. I am using a 12v 20 amp power supply for masso and other small switches of my cnc. Please let me know if there are special requirements of the USB distributor that i can buy. I have tried it with USB 3.0 distributor also... But still the same problem.