[gearsoup]

I will be getting 2 more CNC machines in the next few weeks. (Giving me a total of 3 machines, 1 lathe, 2 mills) All are fanuc controls.
What is a cheap, easy way of sending programs to the machine from my laptop? We have a wire running constantly running to our current mill (up the wall, across the ceiling, down the wall, to the machine). Is it possible to have similar setups for the other machines? I really don't want to be moving wires around, or invest in the $$$ for a wireless setup....
The first shop I was in had some sort of KVM switch, where they had one cable running to a paper punch, another running to a plotter, one running to the EDM. You would set the switch to the device you wanted to receive, and presto....

[gar]

070715-1116 EST USA

gearsoup:

An RS232 switch box at your computer with 4 positions, and from the switch box a separate cable to each CNC machine is your lowest cost approach. This only allows communication to one machine at a time. Thus, you can not drip feed ( DNC ), which may last for a long time, to one machine and communicate to any other machine simultaneously.

This RS232 direct connection method is risky because ground voltage differences between machines and the computer may at a minimum cause errors or worse damage to components.

This is less likely if the laptop happens to be unconnection from safety ground. But in this case an operator at the computer could be shocked if there was a short circuit at the CNC.

See my web site www.beta-a2.com for information on isolation.

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[yoopertool]

One thing to plan on is having different machine profiles set-up on your computers communication program. You will have to have different settings for your baud rate and a few other things for each machine. Just a heads up

[gearsoup]

where can I find an RS232 switch box?
I have taken precautions to ensure neither the machine or the computer are at risk. Thanks for the heads up anyway!

[gar]

070716-1133 EST USA

gearsoup:

Here is a source found with a Google search. Which you can do. Computer stores when they existed and were computer stores have in the past carried these, but usually in the 25 pin variety. I have no experience with the company.

http://www.l-com.com/productfinder/f...tep1=D-SUB+DB9

What "precautions" have you taken?

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[BigBobH]

All Fanuc controls use the same cable configuration so why not just have a single 4 meter cable and invest in a trolley and take the laptop to the machines. You could also look at a pocket PC solution such as dncFusion at site www.dncfusion.com. If you want to dnc then you will need a computer next to the machine. There are plenty of good s/hand pcs around for $200.00 that could do the job

[gearsoup]

Well, first off, I highly doubt that I will ever need to drip feed a program. My Johnford SV-40 has the memory upgrade option. The other day, I loaded in 4 programs. They were over 75 pages of text, EACH! I also had several other programs in it at the same time.
I have been doing CNC for almost 7 years, and my partner has been doing it for over a decade. We have a laptop, but it prety much stays at the desk. Check out my website, and you will see why having a computer on a cart isn't much of an option....Especially once we bring in the 2 new machines
The way we are sending and receiving is the same way we both have done it for the last 10 years. Hook up a cable from the PC to the CNC, send the program. The last shop I worked in used this method. They had a cable that was about 250 ft long, and they kept it on a reel. They had about 35 CNC machines. The shop where my partner worked did it this way as well. They have over 75 CNC machines. They did have several laptops on the shop floor, so the "good" machinists could send and receive, as well as do some programing/CAD. Neither of the shops have ever had an issue. We have had power surges and failures while we were sending or receiving. We booted the machine back up, and we haven't had any issues. We are using shielded wire, and that's about it....

[gar]

070717-0653 EST USA

gearsoup:

If you are running a 250 ft shielded cable with direct connection between your computer and CNC you will not be able to send programs at 115.2 kbaud. For a given computer and CNC combination the maximum baud rate is inversely proportional to cable length. Talking about cable length alone without also discussing baud rate and some other factors does not provide much information.

My guess is that you probably operate at 4800 baud. This in turn means your files are not very large. Probably less than 10,000 bytes. 4800 baud allows about 480 bytes per second for a transfer rate. That is 20 seconds. Now increase the file size to 1 megabyte and the time is 2000 seconds or 0.56 hours.

If you use a laptop in the office connected to a CNC and there is no ground pin on the AC cord connected to the laptop logic common, then you won't have much effect from different ground voltages. However, if there is an electrical short from power wiring at your CNC to its frame, then this will put your laptop at whatever voltage to which the chassis of the CNC rises.

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[bborb]

Cheapest way: Buy a 25pin "straight-thru" extension cable, available most computer stores off the shelf. Plug it into your existing cable at the Johnsford and run it to either new machine when needed. Or buy 3 "straight-thru" cables and a 25pin 4port switchbox and set it on top of the Johnsford, inserting your existing cable to the "input" and running the three cables to your 3 machines. Turn switch to the open port when not in use.
Either of these fixes saves you from building special cables (hopefully).
http://www.dalco.com/ProductDetails2.aspx?sku=38615
http://www.dalco.com/ProductsList2.a...73&selection=4

[gearsoup]

the cable we got with our Johnford was a 25 pin, but there were only a handful of pins actually there. Are you saying I don't need the same thing?

[gar]

070718-0657 EST USA

gearsoup:

If you use software handshake, then only 3 wires are required in the cable, and maybe a few jumpers at each connector end. A shield would be a fourth wire. Hardware handshake requires a minimum of 5 wires.

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[bborb]

You don't need the same thing.
The cable you got with the Johnsford HAS the proprietary configuration built in (jumpers, etc.). The "straight-thru" cables are just extension cables. You don't need to buy/build any more "special" cables. The one you have will work on your new machines as well, as long as it is inline anywhere between your PC and machine(s).