DNC help

[Dan@clover]

I been having this problem for sometime now and can't get a handle on it, any suggestions would be great.

 

When I run a long 3D program to our VMC (Tree 1050) machine, I get a buffer error about one hour into the program, sometimes sooner. The error message on the machine tells me it's a buffer error, and to lower the baud rate. I did that and the machine runs out of program.

 

We are using Cimco 5 edit, and the controls on the machine are Dynapath, We tried changing the cables, played with different baud rates and even

changing the filter ratio in MC, (which the machine did not accept.

 

any thoughts would be great.

[jagg2499]

did you try adjusting or shuting of your FIFO buffers?

[Dan@clover]

jagg2499 - FIFO buffers, where do I find it, Still trying to figure out that machine.

[jagg2499]

FIFO buffers are on your pc they are listed under the advanced settings for that com port

[neil qwerty]

The FIFO buffers are on the computer that you are using to send files to the control. They are located in control panel, system, hardware, device manager. Scroll down to "Ports", right click on the port that you are using for DNC. Click on the port settings tab, then click on advanced.

 

Neil.

[neil qwerty]

Damn, too slow again. LOL.

[jagg2499]

thats ok neil your answer was much more complete then mine but better luck next time on the speed

[Dan@clover]

Thanks guys, I followed your instructions and it is set to off, anything else I should be looking for?

[neil qwerty]

Turning the buffers down has always fixed the problem for me. If that doesn't work I would suggest getting In-House Solutions to have a look at your setup, these guys really know their stuff when it comes to DNC. You may want to look at the routing of you wires, if you can, keep them away from high volatge lines. We used to have problems with DNC to our wire EDM machines, it would get so bad sometimes that we'd have to shut all the machines down just to send a program over. Fortunatly that doesn't semm to happen any more.

 

Good luck,

Neil.

[Jim at Gentex]

I agree that adjusting the FIFO buffer settings should do it.

 

One additional word of caution about DNC data transmission. It sounds silly, but make sure your data transmission cable does not pass on top of or too near any fluorescent light fixtures between the PC and the machine. The electromagnetic field generated by the ballast in a typical large fluorescent light fixture can wreak havoc on the data flow through the cable and cause some weird things to happen.

 

[mrk1500]

I had a buffer alarm recently running cimco 5

drip feeding a large surfacing program off the network server to a fanuc 21i-m control running g5.1q1(15 block look ahead turned on). I had a 1/32 endmill so I had the feed set real slow. About an hour in I got 087 buffer overflow alarm.

I took out the g5.1q1 and no more alarm. I think it had to do with the slow feed rate. Just throwing this out there maybe it will help?

X2 MR2 SP1

[Dan@clover]

where do I turn off the block look ahead?

[mrk1500]

Dan,

I'm not even sure if you have it, if you have the g5.1q1 in your program just delete it and make sure you delete the g5.1q0(g5.1q0 shuts off the look ahaed) at the end of that tools operation. I am not familiar with your control so it's kind of a shot in the dark

It did work for my problem

hth

[jagg2499]

Does the question about the block look ahead mean the the buffer suggestion did not fix the problem Dan ?

[Dan@clover]

mrk1500 - The dynapath doesn't read g-code, and I don't see anything in the program that would help.

 

jagg2499 - I didn't change the buffer because it was already off, (should it be?)

 

 

Here is an example of what the code looks like:

 

TEST)$

N1.00(T) PRG NAME - TEST$$

N1.02(T) T06 DIA. - .3750 FINISH....$$

N1.04(T) -- TOOL TIP -- $$

N1.06(T) (SEMI FINISH SURFACE)$

N1.08(9)M06T06$

N1.10(9)E01M03S2500$

N1.12(9)M08$

N1.14(0)X-0.0747Y0.2853$

N1.16(0)Z4.88$

N1.18(0)Z1.3798$

N1.20(1)Z1.2798F35.0$

N1.22(1)Y0.2759Z1.254$

N1.24(1)Z1.2595$

N1.26(1)X-0.0598Y0.2701$

N1.28(1)Y0.2787Z1.283$

N1.30(1)Z1.2863$

N1.32(1)X-0.0448Y0.2721$

N1.34(1)Y0.2639Z1.2637$

N1.36(1)Z1.2666$

N1.38(1)X-0.0299Y0.2564$

 

Thanks guys, your suggestions are really great.

[Surface]

It seems funny it would run for an hour and then give problems, unless the machine is doing something different than it was doing during the first hour.

Perhaps it's as simple as the computer going into a sleep mode or the hard drive shutting down. What are the power settings on the computer?

[Dan@clover]

surface - I turned sleep mode off, and all the power settings are set to never.

 

Thanks, I given it a shoot.

[jagg2499]

Dan your right it should be off but i have also seen it need to be on but turned down all the way (just another suggestion) .......... also your first post said you tried changing the cables how long are your cables? and are they shielded? or running close to lighting like Jim said earlier ?

[Dan@clover]

The cables are not shielded, Just run along the wall, no fluorescent lights around that area. The first VMC is has about 15 feet of cable, and the problem VMC about 30 feet. We had in-house here a few years back, they changed the cables and still the same.

[jagg2499]

has the machine always had this problem? ...... i would try to narrow down the problem to either the pc or the cable or the machine

[Dan@clover]

Before I started here they were using something different than Cimco edit, not sure what. When I started Cimco was loaded and I was told that's what were using. Ever since I been here it's been a problem (about 5 years). Everything but the machine itself has been changed, new cables, new pc, new software.

 

I'm happy to say that with all the suggestions you guys have given me, The test program has been running fine (knock on wood).

[jagg2499]

in that case i would try maybe a really short cable and a laptop right at the machine as a last resort. Is there any consistancy with the problem happening like certain time of day or certain things going on in the shop?

[Dan@clover]

The program has been running all afternoon, no errors . Thanks for all your help jagg2499, mrk1500, Jim at Gentex, surface and neil qwerty.

 

You Guys are great

 

 

[jagg2499]

your welcome ........... but what did you change that you think fixed it ?

[cnc-guy]

Another thing that happens from time to time, mostly with Mazatrol controls, is that some PC's COM ports don't send out a strong signal, so it may communicate for a certain period of time and then the signal seems to fade out.

Adding a separate PCI COM port or using a multiport serial board can sometimes solve this type of problem.

Shielding is a must for most shop environemments, make sure the shielding is being used (soldered to the machines DB25 metal connector). Also, look out for things out of the box, once installed a wireless system that went down every weekend, only to find out that a big metal foundary close buy did there metal meltdown by arc electrodes on the weekend creating havoc with wireless signals (cellular, internet, you name it ... and DNC!!!)

hope this helps ...