Fanuc 11s have parameters that set which port, and which protocol you will use for input and output in both foreground and background modes.
Note that CD4 on the masterboard is I/O RS232C interface 2, and CD1 on the monitor is I/O device 1.
Check the following:
- Parameters 20 & 21 (foreground I/O - you want 1 or 2 for interface 1 or 2);
- P22 & P23 for background I/O (once again 1 or 2).
- P5001 for which I/O device number is attached to RS232C interface 1,
- P5002 for 2 etc.
Then check the port group (device number) you are using (if I/O device 1 then),
- P5110 = 3 (DC codes are used and feed is not punched)
- P5111 = 1 or 2 for stop bits
- P5112 = Baud (10=4800, 11=9600) <- I have noticed that 4800 is the effective max throughput rate BTW
Then check the cable - null modems are needed with lines 6, 8 & 20 jumpered (you get a CD or 86 alarm if buy an off-the-shelf null modem cable in other words).
Finally, check the port itself - the RS232C driver chips (75188 is the transmitting driver and 75189 is the receiver chip). Use a LED mini-tester to see if the port (TX is blown). Check our website listed below for wiring diagrams of Fanuc ports.
Memex Automation Inc.
PS: We make DNC and memory upgrades for Fanuc 11s, so we know these controls well (see www.memex.ca).