Is networking ok?

**jharvey407** · 06-11-2011, 10:03 PM

I am in the last stages of building my CNC router. I am using Mach3 for control and I am stripping down the computer to use it exclusively for machine control.

Will having the CNC computer networked to my design computer cause any problems, such as missed steps, or is it ok to use it to control the router while the network is active? The network will not be connected to the internet. It is simply for transfering files between the two computers.

I have been using a USB drive to transfer files but it is a bit cumbersome.

Thanks,
James

**Mogal** · 06-11-2011, 10:36 PM

I do both... Use the USB, and have the CNC computer networked.
I have the internet available on it as well and seems to be ok.
Although, I do NOTHING with the computer while its working.
(Windows updates and everything else is disabled)

hth
Chris

**ger21** · 06-11-2011, 11:07 PM

I have my old 1Ghz PIII connected to my home network. I have a folder shared on it, and copy g-code to it from this PC in the house. No problems.
Back in the early days of mach3 (or Mach1 or 2) it was suggested that the speed setting of the network card be set to a fixed speed, and not "auto", but I don't think it's really an issue anymore, as it's been years since I've heard it mentioned.

**WayneHill** · 06-11-2011, 11:11 PM

James,

CNC files on my CAD/CAD workstation are transferred to my Mach3 PC through the network shared connection direct to the GCode directory. I also remote connect back to my main CAD/CAM workstation for any program updates.

**mvcalypso** · 06-12-2011, 01:05 AM

Hi,
In my experience, a network runs fine with mach.

However, since you asked,

there is one thing, directly related to the use of ethernet network adapters, which I know of that **could** (but probably won't) cause a problem with mach... auto speed negotiation with the ethernet hub.

For some cheap ethernet adapters, the vendors use "low quality device drivers" (I just call it crappy code) and they turn off interrupts during auto speed negotiation. If you see an issue with mach pulses while using the net, you can change this behavior from "auto" to the highest speed the hub/switch that the adapter is connected to supports. This locks the adapter to a single speed and avoids the possible auto negotiation problem.

To change this, go into network connections and open the properties for the network adapter. The details will vary by win version and net adapter vendor - so I can't give exact steps.

in the configuration for the ethernet adapter, look for the advanced tab (or so it's called on XP), and see if there is an entry for "media Type"
This controls how the adapter handles the different ethernet speeds - usually it is set to auto (so it self selects 10 or 100 or 1000 depending on what it is connected to).

Most name brand enet adapters these days are pretty good and this does not bite you.

Wireless LAN adapters can have a similar issue when they scan for Access points and do RF channel scanning. Some of the cheep chips will turn off interrupts while scanning channels- and if they do the brute force "scan all channels at once" approach, this can be several seconds. The name of this control in settings is different by vendor.

Stick to a wired connection (much better for a cnc control) and you can forget about teh WLAN issue.

Dave

**jharvey407** · 06-12-2011, 08:19 AM

Thanks guys.

A network will speed up the design process. I find myself having to go through a couple iterations of design/g-code before I get everything right, and using a USB drive has been cumbersome at best.

I'm going to set up a small network in my shop. It will be just an ethernet switch and 2 computers. I'll configure everything manually, including the speed.

I'll let you know how it works out.

J

**wildwestpat** · 06-12-2011, 09:38 AM

A simple alternative approach with much reduced risk is to use a switch on the LPT input of your CNC processing machine and to switch the input between your two computers. Use one PC for development, testing, surfing the net, accessing PDF files etc. and the other for production of parts.

The machine running CNC for production of parts having nothing other than the bare essentials for running Mach3 loaded and the update, hibernation configured to give Mach3 100% use of the processor.

These switches are available from computer stores and off ebay for less than $20. And were used for switching two or more PCs to a single printer. They have the standard 25 way connector but there are a few that do not connect and switch all 25 pins. The switch in the low cost ones is mechanical and there are some exotic electronic ones. Buy an UPS for the CNC PC and relax as I like the zero risk approach. I also like to drink my tea in peace not hovering over a CNC run not that human intervention will save a part that has been screwed up when Mach3 did not have full use of the processor! It only takes seconds to transfer the code with a USB stick and it also enforces a back up plan as you will have the code on two isolated machines.

Yes Mach3 will run with a network and you can also do other things on the PC at the same time BUT there is the opportunity for a glitch.

Application sharing and priority is not well handled by Windows and can cause hiccups in the CNC operation. If you are OK with scrap parts on the odd occasion then by all means use the network - multi task and browse the internet or play music as most of the time you will get away with it as CNC does not require many mips to operate but does require access to the processor without appreciable delays. A small low powered desk top is also cheap even if bought new.

Good luck - regards - Pat

**ger21** · 06-12-2011, 10:09 AM

A simple alternative approach with much reduced risk is to use a switch on the LPT input of your CNC processing machine and to switch the input between your two computers. Use one PC for development, testing, surfing the net, accessing PDF files etc. and the other for production of parts.

He wants to transfer g-code from one PC to another. I don't understand how using a parallel port switch helps this at all?

As Dave and I both said, Mach3 typically has no problems with networking, and if it does, it's can be easily remedied by turning off the "auto" setting.

**wildwestpat** · 06-12-2011, 12:36 PM

Hi Gerry

Sorry but I do not agree that Mach3 can co-exist with networking. It all depends on the acceptance or avoidance of risk.

The network is able to access the PC that is running the CNC control of the machine making the part and that can certainly cause trouble.

Yes it is practical to withdraw the network plug to stop unwanted access to the machine running Mach3 and cutting parts.

There are many people who do all sorts of things with the PC whilst it is running code to cut parts and they get away with it but the risk remains. The higher the processing power of the PC and the faster the disk read write the risk decreases but is not eliminated. Windows is poor at multi tasking and that is what the network connection can cause in response to commands from the network.

Regards - Pat

**ger21** · 06-12-2011, 12:48 PM

That's fine, to each his own. I generally agree with you 100%, that absolutely nothing should be running but Mach3. But I use networking on a "marginal" PC just fine, and I read almost every post on both the Mach3 Yahoo group and web forum, and haven't seen anyone having issues due to networking in several years. So I personally don't think it's an issue. You do, that's OK.

But can you explain about how you use the LPT switch?

**jharvey407** · 06-12-2011, 01:50 PM