Drip feed, DNC?

[Greg_B]

I am using Mastercam v9. I've looked thru the help files but don't see any info on how this is done (breaking up a large file).

If I were transferring (running) a file from my laptop thru a printer cable to the rs232 port, would the file run no matter the size? It looks as though from the Operations Manager I would pick a toolpath, click on 'post'. In the Post Processing window, I would just choose 'Send to machine'? If so, how would I know if the parameters in the 'Communications' window were set right?

Greg

[Steve Arteman]

Greg,
Use file next menu communications, set the setting to the machine tool settings
Steve
www.cad2cam.net

[ObrienDave]

Well, OK here goes...

#1. If you are drip feeding a program to the CNC control, then YES you can send a file of nearly unlimited size.

I say nearly because you would be limited to the available hard drive disk space on your computer.
I have personally sent part files of well over 100MB to a FADAL with only 32K of memory with no problems.

#2. A printer cable will NOT work.

A printer cable is normally a Centronics PARALLEL connection.
What you need is a SERIAL cable.
Unfortunately, most laptops do not have a TRUE RS232C serial port anymore.
I think what you are referring to is a USB printer cable.
For that you would need a USB to RS232C adapter.

#3. In order to know that the communication parameters are correct, you would have to be able to find the settings in the machine control.

From there, either change the control parameters to match the MasterCam settings, or, change the MasterCam settings to match the control settings.
Remember, the faster you want to send the data, and the longer your cable is, the more errors you are likely to encounter.
My suggestion is to set the control and communication parameters to as fast as the SLOWEST one allows.
For example, Mcam9 will allow 115200 baud.
If the control will only do 38400 then you will have to turn down Mcam to match the control.
Once this is done, then you want to send a part file to the control.
If you see garbage characters, or you get communication errors, then you need to slow BOTH control and Mcam parameters down until you don't get any errors.
I also suggest you send the same file back a forth a few times to make sure parameters are correct.

Now, before I get flamed by anyone, I have to say that I have not done this stuff in a couple of years, so what I have posted may be becoming a bit dated.
However, the principal information for machine communications is, I believe, correct.
PLEASE remember also, to check out your parameter settings and file transfers BEFORE you actually try to cut a part.
I would hate to have you, or anyone else, come back and say "your information was full of CRAP", and I crashed a part or cutter or the machine.

The point is
#1. TEST
#2. TEST
#3. TEST
And when you think you are correct, TEST AGAIN!!!

Happy chip making

[Greg_B]

Thanks for the info, Steve. I'll be checking out your site.
Greg

[Greg_B]

Thanks Dave. I'll be testing this next week. I'll post the results.

[Greg_B]

Dave,

I plugged the serial cable in and chose 'Send to machine' when I posted the file. It showed that it was transmitting but the controller never received it. When I tried to find the file on the laptop from the controller, all it let me see was the hardrive and a: drive on the machine. Never the laptop. I'll try again next week.

Thanks,
Greg

[ObrienDave]

Try using HANDSHAKING
There is SOFT (DC1, DC2, DC3, DC4)
And there is HARD (Uses hard wired control lines, which I don't think a DB9 connector supports)
All my old machines used a DB25 conector.
I think there is also a setting to use both.
It's been a while since I did this stuff.
I also used Hyperterm, which isn't available in a free version anymore.
Any ASCII terminal program should work.
What control is the machine using?

[Mike Mattera]

The best advice I can give to anybody setting up an RS232 connection is this... Always start by sending the program from the machine, to the PC. Punch in a little 10 line NC program and send it to the PC. This way you know the code and format is OK.

If you try sending the file from the PC to the Control, you fighting several problems.
1) Your RS232 parameters might be wrong.
2) You dont know if the code format is bad.

You could be experiencing communication problems because the code your sending is not correct for the control. By sending the code from the Control, to the PC, you eliminate that problem and you can focus on the RS232 parameters.

Once you can send it out successfully to the PC, re-name it, and send it back to the control.

Mike Mattera