DNC/Drip Feed

[rsfairman]

I've been getting familiar with a FANUC OM knee-mill from about 1991. With the help of people here, I've been able to download programs from a PC to the mill, and that's been working great.

Now I want to use DNC (drip feed). I've found some information on the net, but it's not clear to me what to do. Apparently, G127.5 is an important thing on the ladder. It does appear on my machine, in this context:

   F292.3      R400.5        F292.5          G127.5
---- [ ] ------ [ ] -------- [ \ ] ---------- ( ) ----
                        |                |
---- [ ] ----- [ \ ] ---|                |--- ( ) ----
   G127.5      R400.5                        G242.3

If it's important, the F292.5 appears in a more intense green on the CRT. When people talk about setting 127.5, do they mean setting bit 5 of parameter 127?

In other places it sounds like there should be a toggle switch somewhere to enable DNC. I've looked at the electronics in the case, and there's no obvious switch, but I didn't want to prod too deeply for fear of causing damage. There aren't any keys on the panel either that seem likely. In a few places on the net, it sounds like there may be a strange combination of keys that one presses. In any case, I am lost.

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[dcoupar]

There may be a TAPE mode, which sometimes is used for DNC.

On some machines, I've seen soft keys that activate the DNC.

[stucapco]

Yes, TAPE mode, in the settings page there should be an option INPUT DEVICE = 2 (2~3:RS232C 11:ASR 13:RS422). Set to "2" and use TAPE mode. TAPE mode, then start, it should wait for input. Then start the drip. I depend on this when the code file size is to large.

Luck.

[rsfairman]

Part of the problem is that I do not have the correct manual from the manufacturer. I have several FANUC manuals, but no manual for this particular machine.

I'm not sure what "tape mode" means. There is a parameter, TAPEF, and I tried to set it to 1, but the system won't let me. Yes, I changed PWE to 1 first, but whenever I try to input a 1 for TAPEF, the system just ignores it.

There is no parameter for "INPUT DEVICE." There is one for I/0, and it is set to 2, but there's nothing called "INPUT DEVICE."

Here's a photo of the panel, in case that helps anyone to know what the possibilities are.

[cjfisher]

Rsfairman,

As you are already able to upload programs you don't need to (or want to) change your input device parameters (well maybe the baud rate.. you may want to speed that up). I have been playing with a friend's machine that has the OM controller. The manual states that the TAPEF is a tape format parameter so you probably don't want to change that one. From other posts I have seen the 127.5 is physical location aka input that can be toggled by changing the bit. I seem to recall that it came up in several posts regarding 6m machines. If I can find them I'll add the info to my post.

http://www.cnczone.com/forums/fanuc/...ip-feed-4.html

Posts #41 and later may be of some use. Parameters and locations may be different, but the method is what will be most helpful. You will need to track through the ladder on your machine to see what activates the G127.5 coil. Could be hardware or software or a combination of both.

http://www.cnczone.com/forums/fanuc/...cnc-forum.html

Not as useful, but it does indicate that the OM control is capable of DNC.

Charles

[rsfairman]

Charles, thanks for these links. I read them (and so many more!). At this point, I've spent far too much time messing around with this. Either there's something arcane that I need to do to use DNC or it's just not possible on this machine. It could be anything from a strange button combination to ladder programming (which I am not equipped to do). For now, I will live with lack of DNC, but I sure would like it.