O/T DNC or Drip Feed

[jspangler]

Hi

Just wondering what the difference is between DNC and Drip Feed? I understand that the Drip feed feeds the control lines of code, as needed from a seperate source. What does DNC do? Are there any benefits?

 

Thanks

 

John

[cadcam]

Basically DNC is Downloading to the control and Drip feeding is useing the computer to hold the program and give it to the Machine as needed.

 

this use's the buffer to hold the program and as you use the code it removes it from the buffer and adds more.This keeping the door between the machine and the communiacations open at all times.

 

As in direct load being DNC opens the door loads to the moemory and closes the door.

 

Hope this helps some.

[Thad]

Jay, I've got to disagree with you on this one. I believe DNC is the same as drip feed. Actually, "drip feed" is just a slang term for DNC (Direct Numerical Control).

 

Thad

[Brendan P]

Here's my take on it John.

At my place,99% of our programs are recieved to control and sent to the computer using what's called DNC.

As you know via rs232 port and cable.

This works great if you have decent amount of "memory space" in your machine control and programs are not real large.

 

However,when working with large G-code files,you may not be able to fit one program into the control because of its large file size.(typically surfacing mold cavity stuff)

 

This is where you would want to "drip feed" the program into the control (as jay stated) from the computer via rs232 port.

Doing it this way,you are not storing any of the program into the memory,so you don't have to worry about it not fitting into the control.

 

If you are using small programs and have decent memory space at the machine control,I dont believe that you need to "drip feed" your programs.

 

HTH's

[Eeyore-nonhuman forum member]

Drip feed and DNC are the same thing ,IMHO .

I am with Thad

[cadcam]

Thad ,Igree with you. but when you work with customers they go all over the place and you will say DNC and they say I want to just download the program to the machine so you wind up calling it drip feed from the computer and saying that DNC does both .

So you have to have a way to explain it to the customer whan you talk about getting thee programs into the machine.

 

So this how i look at it.

 

So it's all good.

[Thad]

+1 to everything Brendan said. We call it either DNC or "run it from the control." It's one or the other.

 

quote:

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So it's all good.

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+1 to you too, Jay.

 

Thad

[Steve Landkamer]

Jay,

In-House has a great site about "DNC" check this link out: DNCSoftware.CA

 

When I am talking to customers I try to avoid the "DNC" word and leave it at RS232 communications weather they are "Drip Feeding", "Spoon Feeding" or just plain old dump to memory.

 

HTH

 

Steve

[M. Anderson]

Well, here's my .0002

 

I have worked at quite a few places over the years, as such I have seen quite a few different systems for getting programs into CNC's.

 

One place done everything off floppy disks. Simple and it worked - just had a **** load of floppy disks laying around!

 

Another had a "DNC" (Distributive Numerical Control) system that you used one main computer in that department - selected your machine - and sent the program to your machine over RS232 ports on a multi port card installed in the computer and hardwired to each machine. I don't know if that system allowed "Drip-Feeding" or "Buffered Input" - we did not do that. I would think it would?

 

I also work at a place that used a "DNC" (Direct Numerical Control) system that when you switched jobs - from the "CNC" controler, you could enter a path and program name from a job run sheet that was given to you each day or you could also scan thru the programs in a folder specifically avaliable only for that machine - highlight the proper program - hit the "load or buffer" soft key - the control would then download or buffer the program for execution. The programs were stored on a main server up in the main office. Neat system - all of it was over a RS232 system also - kind of slow loading the program was the only fault I had with this system.

 

Now that I work for myself - I use Cimco Edit that comes with Mastercam and send the programs over the office network to a "MOXA BOX" (serial network box) then that is connected to each machine. I can send the entire program or I can "Buffer" the input to the machine. Depends on the size of the program and if it will fit in the machines memory.

 

You can call that whatever - DNC - Drip-Feed - Etc...

 

All I really care is, IT WORKS!

 

Later,

 

Mark Anderson

[Ying Jiang]

DNC - Does Not Compute

[jspangler]

HI

THanks.

I agree that as long as it works, fine with me!!

 

Now does anyone have any tips for getting a laptop (with a few keys missing) that is running windows 95 to communicate with my desktop that is running XP home?? The laptop does great for drip feeding, but feeding it floppys definitely kills the convenience factor!!

 

Thanks

 

John

[Thad]

John, just network them together. I can't give you any info beyond that though. Our computer guy handles that stuff.

 

We have old 400MHz computers running Win95 at each machine. We send files there from the MC seat, and then either send them into the control or DNC from there.

 

Thad

[Eazy]

quote:

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We have old 400MHz computers running Win95 at each machine.

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400MHz is like a rocket ship to us. Most of ours our Pentium 90's. Does the job perfectly well though.

[cadcam]

John I thought Rob was helping you?

All this can be done.Is there a network card or a RJ45 plug in the old laptop?

 

Get your self a RJ45 crossover cable.

Or if the old one has USB you can do usb to usb with the right cable.

 

Also you can get a newer laptop on ebay cheap.

[jspangler]

Hi

I was using a PC card type ethernet connector on the laptop (client), and a crossover cable to the desktop (server). THat's where the problem is. The laptop transfer files and drip feeds using cimco perfectly, but I just can't get the network to work right and have been using floppys. The laptop doesn't have enough ram to use anything other than W95.

 

Basically, I need a computer guy to help with this one. I don't have the patience, and win 95 is what made me switch to Mac in the first place.

 

Thanks

 

John

[Müřlıń®]

I always took DNCing to be drip feeding the control.

 

Adding a part program to the control..... I always called that storing a program....

 

 

Murlin

[Thad]

quote:

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400MHz is like a rocket ship to us.

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Yeah, they really scream, don't they? We've got a few 133 MHz boxes also. I didn't know how good we had it.

 

Thad

[PE @ IHS]

DNC refers to communicating to a CNC machine, generally through the RS 232. You can either load into memory or drip feed. Either way, you are using DNC to get the file to the machine.

 

This is accomplished by specific software and hardware which takes cnc specific settings (baud rate etc.) into consideration.

 

A floppy drive would not be considered DNC.

[Thad]

I thought I'd look up DNC in one of my college books. This is from "Computer Numerical Control - Concepts & Programming" Third Edition, by Warren Seames (copyright 1995).

 

quote:

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Direct numerical control

involved using a computer as a partial or complete controller of one or more numerical control machines. Although some companies have been reasonably successful at implementing DNC, the expense of computer capability and software and problems associated with coordinating a DNC system renders such systems economically unfeasible for all but the largest companies.

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And that wasn't even 10 years ago!

 

Thad

[Müřlıń®]

Thad that was a good one....lol.....

 

 

Back in the 50's it took a whole city block of warehouses to store the computing capabilities of what sits on our desk right now I guess whoever wrote that article was stuck in the 50's.....

 

Murlin

[cadcam]

You Murlin ,I am with you preatty funny.

Sense now you can DNC from a PDA.