[Jeremy_Sawatzky]

Hello everyone

I have a new to me Daewoo Lynx 200B lathe, I need some assistance in troubleshooting the RS232 Communications. The machine uses a Fanuc 21-T control.

I would like to say I have tried absolutely everything under the sun to try and communicate with the machine but maybe I missed something.

I have tried the following and a million combinations of Baud rates, parity, stop bits, flow control, cables, com ports, software etc.

I cannot send or receive a single byte of information between the cnc and my pc.

My setup is a usb to serial db9 cable that I have confirmed works by using it to send files to and from a different machine. I then use a custom made db9-db25 rs 232 cable that again has been confirmed to work.

When I try to send files to the CNC, the leds on the usb serial cable blink indicating transfer is occuring but I dont believe that any data is being recorded by the cnc control. The menu on the Fanuc display blinks LSK like its waiting for data but nothing comes through. I have also tried sending a file from the machine to the control but again nothing comes through. It seems to me that the Fanuc board may just be toast. - as far as I know this machine came out of a running cnc shop.

Any suggestions?

[Jeremy_Sawatzky]

If it helps anyone in the future.

I discovered that I needed to have my cable cross pins 2 and 3 instead of 2-2 and 3-3.

No idea why this machine is this way. But I can now send files to and from.

[fc60]

Greetings,

Your solution brings a FlashBack to me.

Years ago I had a flatbed plotter that used a "Null" Modem cable.

I bought a box of connectors and a crimp tool to make my own cables.

Like you, I do not know the electronics well enough.

Cheers,

Dave

[drdos]

If it helps anyone in the future.

I discovered that I needed to have my cable cross pins 2 and 3 instead of 2-2 and 3-3.

No idea why this machine is this way. But I can now send files to and from.

Because pin 2 is send data and pin 3 is receive data. You were trying to send to a "send" signal.