Communication Problem

Good day to all.

I have managed to setup and connect a CNC mill machine (Mitsubishi Meldas 60) to a PC.

When i am sending a program from PC to CNC everything is ok, but when i am sending from CNC to PC the transferred program either missing spaces and characters (Pic.01) or some characters are altered (Pic.02).

In the pictures you can see a very simple program. I i wrote it and sent to CNC and then tried to get it back to PC.

I have tried:
- To change many parameters mainly in output
- Tried 2-3 DNC free software and 2 different PCs
- Tried to change handshake
- Tried to change the port settings and the FIFO

I also checked the wiring of the 9pin/25pin RS232.

Any ideas what else to try?

Thank you in advance.

One of your RS232 parameters, probably not baud rate, but one of {data bits, parity, stop bits, flow control} is likely not consistent between the machine and your PC. Windows is very touchy about these, you can set them at the driver level or in the program you use to transfer. When text is garbled like that usually the problem. Try and avoid RS232 flow control if at all possible. Also, stick to 9600 baud even if you have the option to go faster, it's where everyone made their hardware work in the old days.

Check out http://dl.mitsubishielectric.com/dl/fa/document/manual/cnc/bnp-b2229(eng)/bnp-b2229(eng)e.pdf, page 112 for parameters with settings if you don't already have this manual.

Good luck!

xyzzy said:

One of your RS232 parameters, probably not baud rate, but one of {data bits, parity, stop bits, flow control} is likely not consistent between the machine and your PC. Windows is very touchy about these, you can set them at the driver level or in the program you use to transfer. When text is garbled like that usually the problem. Try and avoid RS232 flow control if at all possible. Also, stick to 9600 baud even if you have the option to go faster, it's where everyone made their hardware work in the old days.

Check out http://dl.mitsubishielectric.com/dl/fa/document/manual/cnc/bnp-b2229(eng)/bnp-b2229(eng)e.pdf, page 112 for parameters with settings if you don't already have this manual.

Good luck!

Click to expand...

Thank you for the reply.

I have checked Baoudrate:9600, Parity:None, Stop Bit:2, Character Length:8 and also unchecked the FIFO option in the advance settings of the port. I also checked the cable wiring on both end and seems ok.
The same settings are in software, I/O device parameters and computer link parameters.

I can not understand why the sending (PC->CNC) works fine but the other way around has problems, although the settings are the same.

VSBill said:

Thank you for the reply.

I have checked Baoudrate:9600, Parity:None, Stop Bit:2, Character Length:8 and also unchecked the FIFO option in the advance settings of the port. I also checked the cable wiring on both end and seems ok.
The same settings are in software, I/O device parameters and computer link parameters.

I can not understand why the sending (PC->CNC) works fine but the other way around has problems, although the settings are the same.

Click to expand...

After many tries i finally got it to work, by changing Baudrate, Parity, Stop Bit and Character Length. It works (sends & Receives) but when it receives a program it has no spaces at all. Although when i send it(the program i received with no spaces) back it has spaces!

I am asking just out of curiosity... It works fine (I will perform many test on Monday just to be sure)

Thanks a lot xyzzy for the help!