Fanuc 31I RS-232 Alarm "CANNOT USE I/O DEVICE"

Hi,

I have a Toyoda horizontal machining center with a Fanuc 31I controller. I'm attempting to get the serial port setup so that I can send programs to the machine over RS-232.

The company that we bought the machine from had this working using the same cable and port.

I've made changes to the below parameters to match the computer but still get an alarm saying "CANNOT USE I/O DEVICE".

Parameter 20 (I/O Channel) = 0
Parameter 21(out channel F.G.) = 0
Parameter 22(input channel B.G.) = 0
Parameter 23(out channel B.G.) = 0
Parameter 24= 0
Parameter 100=00001010
Parameter 101= 10000001
Parameter 102(Input/Output Device) = 0
Parameter 103(Baud Rate) = 11
Parameter 110(Separate Control of I/O Channel) = 1

Any suggestions for what else to look into would be greatly appreciated!

Thanks,