We have 2 Hitachi Seiki Horizonal Mills with Fanuc 11m controllers.

I have the RS-232 serial port wired like any other Fanuc 11m controller but the machine can only recieve not send back to the DNC software.

Someone from the shop said that a repair tech plugged a tradional null modem cable into the machine and his laptop and it worked.

I dont get it.

What am I doing wrong.

Any help would be greatly appreciated.

Thanks Much

Mike