Need Help!- Buffer Overflow

[ar89]

Hi,

We have a Denford TRIAC Slanted Bed Lathe Machine with a Fanuc 21i controller.

When i try to download a program from my computer to machine i get an alarm stating "Buffer Overflow".
This alarm only comes when i download G-code generated by ProE or some other CAM software.

Kindly, if anyone can help me out!!! I'll be grateful

[dcoupar]

Your PC is not stopping transmission fast enough for Fanuc. You might want to disable the FIFO buffers for the COM port you are using. This usually solves the problem.

Right-click on My Computer and click Manage.
Click Device Manager
In the right-hand pane, click on the + next to Ports (COM&LPT) to expand it.
Right-click on the COM port you are using and click Properties.
Click on the Port Settings tab.
Click Advanced
Slide both slider bars all the way to low.
Check "Do not use FIFO buffers".
Click OK all the way out and then re-boot your PC.

[mfgbydesign]

Be certain your DNC software and cabling is set up for hardware handshaking. (Xon Xoff).
Drop the baud rate. If it's 9600 set it to 4800 or 2400.
It might help to at a 5 msec. delay after sending each block (DNC setting).

[ar89]

Thank u so much dcoupar and mfgbydesign!!!!!

Problem is solved by your methods. But now a new problem has arisen.
Programs generated by CAM softwares are very much big in size and mostly exceeds lathe program memory. It indicates that lathe has a memory of 5040-char.

Is there any method to reduce the size of the code generated or to increase the memory of lathe???

I have memory cards available upto 1GB. I was thinking can these memory cards be used as an extension of lathe memory???

[dcoupar]

Originally Posted by ar89 Thank u so much dcoupar and mfgbydesign!!!!! Problem is solved by your methods. But now a new problem has arisen. Programs generated by CAM softwares are very much big in size and mostly exceeds lathe program memory. It indicates that lathe has a memory of 5040-char. Is there any method to reduce the size of the code generated or to increase the memory of lathe??? I have memory cards available upto 1GB. I was thinking can these memory cards be used as an extension of lathe memory???

If your CAM system is outputting sequence numbers you might be able to turn them off when posting. This could save up to 5 characters per block.

Also, if your control has a PCMCIA slot next to the LCD, you might be able to use a PCMCIA-CF adapter and Compact Flash card with the DNC-CRD to run large programs from the card.

[mfgbydesign]

I don't have much experience setting this up, but most DNC software will allow you to "drip feed" programs larger than the CNC memory. If your handshaking is set up properly the DNC will wait until the CNC tells it to send more data.

[jimmy111]

You should be able to. I changed some parameters on mine and now I can drip feed from the FA card.

First find out where the remote button or switch is on your machine. This switch tells the computer where to look for the part program. On some machines it it hard to find. It is usually a machine manufacturerr supplied switch and wont be in the Fanuc manuals. Look in your Machine manufacturer documentation. If you dont have this switch you cant dnc from the FA card. All MAchines I have seen except one have had this button. It is not always marked.

Change these parameters:

138.7 = 1
3404.2=1
6080=0
6300.4=1

Set the comunication port to 4

It seems to work a lot better if you format your card in your controller first.

Insert the card in the machine and reboot the control

Home everything.

Push automatic and set the switch to remote.

Push program button
push the + softkey untill you see the DNC-CD soft key show up. You might have to push other keys to find this but it is there.

You will see a list of program numbers on that are on the FA card.

Like this:

0001
0002
0003

Enter the number of the program you want to run.
You will see another soft key pop up DNC-ST.
Push this key then when you are ready push the cycle start button and the program will start.

Do not insert and remove the FA card while the controller is on. Turn the controller off first.

I just finished a 150 megabyte part profiling program that ran for a week. So you can run large programs.

[ar89]

Originally Posted by dcoupar If your CAM system is outputting sequence numbers you might be able to turn them off when posting. This could save up to 5 characters per block. Also, if your control has a PCMCIA slot next to the LCD, you might be able to use a PCMCIA-CF adapter and Compact Flash card with the DNC-CRD to run large programs from the card.

Yes sequence numbers are also being sent....how can i turn that off??
and i have PCMCIA-CF adapter and Compact Flash card...but what is DNC-CRD??