rs232-usb

ace of spades · Post by **ace of spades** » Thu Jul 30, 2009 5:44 am

Hi all

Can any techno wizz direct me to success?

I need to connect a couple of cnc machine (fanuc and Haas) to a computer. The CNC machines all have 25pin rs232 connections and this specific computer only has a USB slot. The program that I have to send/receive data has to recognise the specific port to send to, thus have to ID from which specific machine the signal is coming from. There are ways around the port issue, but this is how the bossman wants it, any help?

Post by **FZRDude** » Thu Jul 30, 2009 11:12 am

They make cables for this. I must have 3 or 4 of them. Cost about $15-$35 USD.

An no, I do not know of a work around

RUFtech · Post by **RUFtech** » Sat Aug 01, 2009 9:40 pm

When you plug something into a USB port it should prompt you to set up each component plugged in. You might have to go the web sites of the respective CNC machine companies to get the software required for your computer to recognize them. I also have several of these RS232 to USB cables used for different things, mostly for tuning cars.

DAVE · Post by **DAVE** » Wed Aug 05, 2009 8:28 am

I use a USB - serial to get data from my GPS. One thing I noticed is that the com port assigned to the adapter depends on which USB port I plug it into. If I plug it in the same USB port all the time it is always assigned "com2" but when I plug it into the other USB port it becomes "com3".

You CNC program will always want a certain machine to be on a certain comport, although I would imagine that it have an option setting to select a different comport for a particular machine.

It would be a matter of installing the USB-serial adapters and drivers, finding out which comport is assigned to each and then making sure that when the computer is restarted several times that the same comport numbers are re-assigned correctly. THEN you would set the CNC program to use the respective comport numbers that will apply to each USB-SERIAL to each machine..

Does that make sense???

duke22 · Post by **duke22** » Wed Aug 05, 2009 8:59 pm

Hi Ace,

Something I've found in the past is that a lot of CNC machines buffer feed through the RS232, they use a signal generated by the control to control the speed of the data stream by starting and stopping it as the buffer fills. A USB port won't support this function and will just pour the data through until the buffer overflows and the machine alarms out.

If this happens your only real option is to find an old PC with a serial port, I used to have one just for that job. Or you can use floppy discs for the Haas or flash card for the Fanuc?

If you need more info let me know, I can probably dig it out for you.

Cheers
Lyle

ace of spades · Post by **ace of spades** » Tue Aug 18, 2009 11:04 pm

Hi Guys, thanks. I got it sorted. I used CNCNet DNC and a couple of USB/Serial converters and a hardware/software handshake: XonnXoff and RTS/CTS.

My 10 main production machines are lined up on the system. I just need to get the remote calling of programs running and I'll have a good night's rest.