Connecting to a CNC machine, pros and cons of USB vs PP vs Ethernet etc.

Both Ethernet and usb are digital so noise is likely to effect both if large enough, i have my uc300 running an inch away from my 2200w vfd and two inches from a honking great 55v toroidal transformer without issue so sounds like your noise may have been in your power supply, were you using ac filters? either that or there was something massively wrong happening in the next room.

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Originally Posted by m_c

however nobody uses it as a communication method between a computer and CNC machine

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Not on Mach 3; but that part of the conversation hasn't been about Mach 3 for several days now! :smile: And, of course, that ethernet motion controller is a computer, but that's not what any of us mean.

On the LinuxCNC side, whilst RS485 is more popular, there's definitely people interfacing their machines to their computers with CANbus.

The hardware's been available for years. There's plug in cards that provide the interfaces plus industrial PC motherboards that already have CANbus and/or RS485 on board.

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Originally Posted by m_c

but you're then into a very glorified parallel port like system.

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Rather unfair and misleading. CANbus gives you something much closer to a PCI I/O board in function - you're not having to do software step generation, and you actually have the ability to read encoders.

To seque this into the topic of the thread:

Approaches that allow your computer to more directly control the machine is definitely of huge value if you've got some complicated/non-standard kinematics going on, but even on a standard perpendicular axis mill then there's a potentially a significant financial saving to be made.

The additional costs associated with Mach 3; Windows licenses, Mach 3 licenses and ethernet hardware motion controllers could buy you all the electronics you need to convert something like a Novamill or Triac, even once you've thrown in something like a Mesa Anything I/O.

LinuxCNC on BeagleBone Black? A back of the envelope calculation suggests that I can have my entire dedicated control computer as well as software and breakout for the cost of the Mach 3 license alone; that's a lot of difference.

I wouldn't normally take the bait, especially from someone who has very little if any practical experience building or running CNC machines, but here goes.

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Originally Posted by Jess

And, of course, that ethernet motion controller is a computer.

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No it's not. It'll be an embedded micro-controller, DSP or FPGA, which nobody who deals with such things will class as a computer.

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On the LinuxCNC side, whilst RS485 is more popular, there's definitely people interfacing their machines to their computers with CANbus.

The hardware's been available for years. There's plug in cards that provide the interfaces plus industrial PC motherboards that already have CANbus and/or RS485 on board.

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But not in the form of communication between a computer and a motion controller. In LinuxCNC the computer is the motion controller. External motion control cards are not available for LinuxCNC, as they defeat the whole purpose of LinuxCNC's realtime kernel.
CANbus/RS485 is just another method of communicating between the controller and drives/IO boards, just like lots of other possible options.

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Rather unfair and misleading. CANbus gives you something much closer to a PCI I/O board in function - you're not having to do software step generation, and you actually have the ability to read encoders.

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And what exactly is a parallel port?
Last I checked, it was simply a bunch of I/O pins conveniently arranged in a standard format, that can be accessed directly by software (I know windows blurs this, but the principle is still there), just like a PCI IO card does.
If you really wanted, you could make a parallel to CANbus to BOB setup, and it would give you a similar setup to using a direct CANbus PCI card, just with more limited IO and speed.

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To seque this into the topic of the thread:

Approaches that allow your computer to more directly control the machine is definitely of huge value if you've got some complicated/non-standard kinematics going on, but even on a standard perpendicular axis mill then there's a potentially a significant financial saving to be made.

The additional costs associated with Mach 3; Windows licenses, Mach 3 licenses and ethernet hardware motion controllers could buy you all the electronics you need to convert something like a Novamill or Triac, even once you've thrown in something like a Mesa Anything I/O.

LinuxCNC on BeagleBone Black? A back of the envelope calculation suggests that I can have my entire dedicated control computer as well as software and breakout for the cost of the Mach 3 license alone; that's a lot of difference.

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And this argument over cost will rumble on indefinitely.
The fact remains for your typical DIY CNC enthusiast, the familiarity of windows based computer systems, means they'll remain the most popular option for the foreseeable future, despite the additional cost.
You've got to remember, a lot of people who build CNC machines, are not computer or electronic geeks.

For me personally, time is money, so although I may save on licenses, the extra time familiarising myself with a new operating system/hardware, is time that could be spent making money. For me running Dynomotion products, a KFlop costs about £230 delivered. For that I get nearly everything needed for a motion controller including some very reliable software, and only need to add a windows PC, which can be picked up for very little. I can have the controller configured and ready to go in a couple hours. If the computer fails (which lets be honest, is usually the weakest link), I swap the configuration files onto a new computer, and away I go again.

Add something like Mesa cards into the mix, and you've then got to start swapping parts around, and hope they didn't get killed when the computer died.

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Originally Posted by Jon.

Both Ethernet and usb are digital so noise is likely to effect both if large enough, i have my uc300 running an inch away from my 2200w vfd and two inches from a honking great 55v toroidal transformer without issue so sounds like your noise may have been in your power supply, were you using ac filters? either that or there was something massively wrong happening in the next room.

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I suspect Jazz's source of interference was a HF Plasma Cutter, or HF TIG welder, both of which will produce and emit interference that will far exceed anything a properly wired VFD will.
If you get the chance, you might want to try firing one up next to your machine, and see if it still remains as stable, as there's nothing quite like a few hundred volt high frequency unsheilded arc to highlight the slightest deficiency in your shielding/grounding/power filtering/communications.

Be interesting to find out. Though a grounded metal enclosure around the controller, which should be general practice, would most likely solve the issue. If it didnt id be suprised and very much suprised if the etherenet controller wasnt effected by such levels of noise.

It probably would be, however Ethernet is far better at handling and recovering from noise problems, as it can handle and resend lost data packets, whereas USB doesn't have that capability. I do suspect USB comms could be improved to handle these situation better, but it'll add cost, complexity, and processing overheads.

I know from various USS discussions, Greg struggled to fit all functionality into the USS, so I suspect it was having to do the bare minimum to handle communication. When it came to the ESS, Greg used a larger FPGA, and I do suspect there may be more going on within it to handle communication problems.

I also suspect other manufacturers have looked at the issues from the USS, and implemented strategies to better handle communication faults, as other good quality USB controllers don't seem to suffer from anywhere near as many communication faults.
You have to remember USS was the first successful USB external motion controller for Mach3, and it did achieve a lot, however I do think it's probably time to retire it, or at least update the hardware.

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Originally Posted by Jon.

Both Ethernet and usb are digital so noise is likely to effect both if large enough, i have my uc300 running an inch away from my 2200w vfd and two inches from a honking great 55v toroidal transformer without issue so sounds like your noise may have been in your power supply, were you using ac filters? either that or there was something massively wrong happening in the next room.

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No offense meant to you Jon but I'm doing this all the time and know all about what or not to do. The particular "next room" incident was actually a Compressor with faulty starter but the more the problem was the USB Smooth stepper had a design flaw so didn't take much to upset it. (It was one of the very first models.!! I've since tried newer versions but still had problems.!)

Regards the uc300 then fire up a Tig or Plasma cutter up near by and see how it reacts.! Vfd's and torodial supplys are nothing and it would be very bad state if they couldn't live along side one or both.
It's the things that go off around the machine that seem to affect USB/PC but what exactly I'm yet to determine and believe me I've looked and tried to put my finger on what causes it.!

End of the day I'm into building and using a CNC machine and haven't got time to chase the many things that can bring it down. What I can do is eliminate using those that don't meet the mark by testing them as I go along building machines.
First test is the Tig/Plasma test and then I work backwards from there.!!. . Very few USB devices Pass this test.!

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Originally Posted by Jess

LinuxCNC on BeagleBone Black? A back of the envelope calculation suggests that I can have my entire dedicated control computer as well as software and breakout for the cost of the Mach 3 license alone; that's a lot of difference.

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Ah ah now we get to the meet of the Beef.!! . . . Linux Geek. . . Wanting to Pick a fight with Mach user's.!! . . . . Well Not happening I'm afraid been there too many times.! . . . Jog on.!

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Originally Posted by Jon.

Be interesting to find out. Though a grounded metal enclosure around the controller, which should be general practice, would most likely solve the issue. If it didnt id be suprised and very much suprised if the etherenet controller wasnt effected by such levels of noise.

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All the machines I build use Metal Enclosures and believe me it doesn't help much. Ethernet isn't affected nearly as much and better Motion devices like CSlabs it doesn't affect at all.
I'm just currently testing the Pokey's 57CNC which uses Ethernet and it survived the Tig test but then funnily enough it threw a little wobbly by E-stoping when I was using the Mig welder.? It's behaved since thou so could have been that and the fact i'm using the 5V signal for E-stop. (plus it's rough wired on the bench)

That thread made me laugh, really. How did i miss it. There is no respect for experience it seems. "Knowledge|" without experience is just a collection of facts or suggestions, from here and there.


I don't know what the hassle is about? Most expensive motion controllers have tried USB and then upgraded to Ethernet controllers. See Galil for example. Even cheap controllers have done the same. So there must be a reason for that.


What happens at low level / cheap/ controllers is that they do the same just like a follow up , after a couple of years, when parts are already cheaply available for the low end market.


Or you say people who make industrial control are stupid and don't know their business.


My blue Makita drill worth 360euro drills holes in steel and my friends green Bosch worth 50 euros drill holes in steel. My Makita can drill 10 years everyday without a glitch and the Bosch will die in month of industrial environment.


As i have pure HF plasma at home let me clear something. Glitches come from not good home grounding, the non shielded mouse and other Pc cables, not from USB or Ethernet cable if they are shielded and all electronics are in a shielded box. So basically both should work if everything to the last detail is well done.


Well Jess, now we know you . You have well presented yourself here. I am half expecting soon to hear that RP is better than ball screw and that HD alu profile gantry is stronger than steel one..

Really id say its down to personal preference. I think if your using an Ethernet controller over usb because of noise its because you haven't taken the correct steps to shield the controller and that you are also happy to have your controller bombarded with noise, just because it can it doesn't mean it should. You may be correct in that ethernet has better protection against noise but that is providing the noise is entering via its ports. If your talking about noise that is infact capable of entering a grounded enclosure then there's no telling how that noise is going to enter the board, but you say it does fair better but with the correct steps either can work so again personal preference.

Bearing in mind a pc usually has multiple usb ports, but can only handle a single ethernet port so its restrained in that respect.

It is down to personal preference.
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However most experienced machine builders, will recommend Ethernet over USB. Over 99% of USB users never have any problems, even when questionable wiring techniques have been used, yet others, even with proper wiring techniques will have endless problems.
The fact is though, the only threads over on the Mach forum about intermittent communication issues are all about USB controllers. I personally cannot remember seeing any involving Ethernet, apart from initial setup problems.
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PCs can have more than one Ethernet port installed, it's just not a common thing to need. There are people who run Ethernet devices over a full network, but ideally you should be dedicating a computer to running a machine and connecting directly, with the same advice applying to USB.

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Originally Posted by silyavski

There is no respect for experience it seems.

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I respect experience. What has seemingly confused you is that I believe that respecting experience means you respect both what it tells you and what it doesn't.

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Originally Posted by silyavski

"Knowledge|" without experience is just a collection of facts or suggestions, from here and there.

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The collorary to that is: "Experience" without "Knowledge" is just half truths and old wives tales. You need both of them.

I'd have liked to present a more continuous narrative, but that's just not possible when the topic is getting changed enough times that we somehow got from the relative sophistication of ethernet and USB controllers to talking about connecting to a machine with a parallel port CANbus adaptor! :grumpy:

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Originally Posted by silyavski

and then upgraded to Ethernet controllers. See Galil for example. Even cheap controllers have done the same. So there must be a reason for that.

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Simple; the cost of doing it compared with the profit of doing it.

With the integration level of modern microcontrollers, an Ethernet port costs about the same to put on a board as a properly isolated USB port. Given there's also a willingness to pay a small premium for Ethernet it's not surprise that things are moving that way.

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Originally Posted by silyavski

I am half expecting soon to hear that RP is better than ball screw and that HD alu profile gantry is stronger than steel one..

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Don't worry, I'm not going to tell you to use coat hangers as rails for your X axis!

...I just wish people had done me the same courtesy on this topic. Especially given that later posts have now repeatedly confirmed what I've been getting shouted down for saying is correct!

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Originally Posted by silyavski

Well Jess, now we know you . You have well presented yourself here. I am half expecting soon to hear that RP is better than ball screw and that HD alu profile gantry is stronger than steel one..

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What sort of steel are you talking about here? Heat treated stress relieved steel.. by far much stronger. Mild steel simply welded up and painted that will change shape over the years then going on its working life span, Aluminum will retain shape and last longer if built well. Hense why production machines always use heat treated steel or aluminum, but you still see people forking out thousands building machines from mild steel obviously going off your assumption, knowing one day they might wake up to find their machine is jammed.

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Originally Posted by Jon.

What sort of steel are you talking about here? Heat treated stress relieved steel.. by far much stronger. Mild steel simply welded up and painted that will change shape over the years then going on its working life span, Aluminum will retain shape and last longer if built well. Hense why production machines always use heat treated steel or aluminum, but you still see people forking out thousands building machines from mild steel obviously going off your assumption, knowing one day they might wake up to find their machine is jammed.

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I will reply in you build thread, cause I see you took that personally. I am also making machines from aluminum just right now.

I had experience of USB a few years back and it was not good, in fact I think the whole USB thing is a scam. The idea was good, every USB device had it's own unique ID number, you plugged it in , the computer asked, "What are you", it replied. "I am a 12345B". The computer searches itself for the driver named "12345B" and runs it. If it cannot find 12345B it asks you where it should look.

The unique ID numbers are free, but, you have to join the USB club before they can be given to you and joining the club is hideously expensive.

To get around that manufacturers used a loophole, instead of coming up and saying, "I am a Model J CNC Controller from Choppit Ltd" they come up and say, "I am a Windows device, usually a serial port or a disk drive". The Choppit CNC control software then has to rummage among the available ports and drives looking for it's controller.

USB does not usually shine because for CNC it is fettered by all sorts of 3rd party software impersonating other things. There was a company called something like "Metrologie" who joined the club and sold their unique ID's at around 10 for £120. They got stomped on PDQ but cheap ID's are still out there if you look :thumsup:

lol.. you what?? so you went on to get ethernet from the tackle shop yeah?

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Originally Posted by Jon.

What sort of steel are you talking about here? Heat treated stress relieved steel.. by far much stronger. Mild steel simply welded up and painted that will change shape over the years then going on its working life span, Aluminum will retain shape and last longer if built well. Hense why production machines always use heat treated steel or aluminum, but you still see people forking out thousands building machines from mild steel obviously going off your assumption, knowing one day they might wake up to find their machine is jammed.

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Jon, you do realise silyavski was taking the michael?
Although I'm not sure about ballscrews being better than RP... :joker:

He might have been but he had just made a patronizing comment about heavy aluminum on a thread of mine seconds before he wrote that one.

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Originally Posted by Jon.

He might have been but he had just made a patronizing comment about heavy aluminum on a thread of mine seconds before he wrote that one.

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I don't see anything patronizing about his comments. There is a bit of misunderstanding due to Silyavski's English, but both his suggestions were valid given the information provided before those posts.

Jon,
it was a suggestion, not patronizing. I saw the need to say to you about strengthening the gantry at glance. But plus that, i spend 2 hours at least thinking about your problem, your machine strength and making calculations, comparing your alu profile data and transferring that data to find the comparative steel profile, then i started calculating deflection and so on...

If you feel i am not right, just ignore what i said, anyway its not an attack or anything personal

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Originally Posted by Jon.

Really id say its down to personal preference. I think if your using an Ethernet controller over usb because of noise its because you haven't taken the correct steps to shield the controller and that you are also happy to have your controller bombarded with noise, just because it can it doesn't mean it should. You may be correct in that ethernet has better protection against noise but that is providing the noise is entering via its ports. If your talking about noise that is infact capable of entering a grounded enclosure then there's no telling how that noise is going to enter the board, but you say it does fair better but with the correct steps either can work so again personal preference.

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My thoughts are the same, +1 for this post.

If people stoped for a second and actually read what was being said, then...never mind... I guess we are all limited in some ways to our own experiences, a level of understanding for things and struggle with other things.

.Me

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Originally Posted by Jon.

Really id say its down to personal preference. I think if your using an Ethernet controller over usb because of noise its because you haven't taken the correct steps to shield the controller and that you are also happy to have your controller bombarded with noise, just because it can it doesn't mean it should. You may be correct in that ethernet has better protection against noise but that is providing the noise is entering via its ports. If your talking about noise that is infact capable of entering a grounded enclosure then there's no telling how that noise is going to enter the board, but you say it does fair better but with the correct steps either can work so again personal preference.

Bearing in mind a pc usually has multiple usb ports, but can only handle a single ethernet port so its restrained in that respect.

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This is the situation Jon from my point of view has someone who Builds machines for others compared to someone like your self who just uses a Machine in a DIY capacity or maybe even Small business venture.
Last Machine I Built went to Scotland which is a 500mile 10hr round trip. I can't afford for to be running up and down the country chasing ghost problems.

It's a FACT whether you agree or not that USB gives more trouble than Ethernet. Just becuase it's working for you without issue doesn't mean it will or does for others. I know this to be true thru experience dealing with Chasing USB ghost's.
I pride my self on the Quality of my Control box's in comparison to many other builders, (and believe me I've been inside a fair few so called Top rated machines costing Several £1000 more than what I build that I wouldn't even turn on.!!) I use correct filtering and ground techniques inside Industrial Steel cabinets along with shielded cables using differential signaling. So I know it's nothing to do with My end but still USB throws Ghost problems and Lockups that cannot easily be explained.

This I can't and Don't want happening on any machine I put my Name on. This is the reason why EVERY component I use when building a Machine gets tested on my own personal machine and for several Months at a time not just a few hours. Could say I torcher them to death or Glory.! . . . NO USB device as passed the Tig/Plasma test.!! . . . . Yes there well maybe some of the Higher end devices that will pass but why should I bother when I've found Ethernet is consistantly more stable on just about every device that uses it. The Cslabs Controllers I use these days are Bullet proof and Never fail or throw wobblys for unexplained reasons.

AND just to prove that USB freaks out when Ethernet doesn't Purelogics PLCM-E3 and Pokey's 57CNC both come with USB and Ethernet connections. The USB on the PLCM couldn't even handle the Mig test before crazyness happened. Ethernet it didn't flinch and when Tig was used it didn't seem to affect it either unless I went right up next to the Controller.!! . . . Pokey's I'm still torchering.!!

I suspect that the underlying UDP ethernet protocol is nearly as error prone as the USB protocol, however, the TCP/IP layer which sits above it and does the error correction is (as has been pointed out) extremely robust so the end result is much better.

I can see both sides of the argument but theory is worth nothing if it doesn't work in practise...

For what it's worth, I've got a 3D printer which is extremely noise sensitive on the USB connection (to the point I now download the print to a memory card and print from that) and a USB CNC controller which I haven't had a problem with but there are dire warnings on the website about using a good quality cable - see https://www.youtube.com/watch?v=NUu9xwDfJ9k

I good example of usb technology would be an external hard drive ... and in my experience these never loose connection. So what is being compared here is not the technology but the boards themselves as proven everywhere, usb is extremely stable... o hang on my ethernet card needs resetting. damn thing screws up all the time. :P

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Originally Posted by FatFreddie

I suspect that the underlying UDP ethernet protocol is nearly as error prone as the USB protocol, however, the TCP/IP layer which sits above it and does the error correction is (as has been pointed out) extremely robust so the end result is much better.

I can see both sides of the argument but theory is worth nothing if it doesn't work in practise...

For what it's worth, I've got a 3D printer which is extremely noise sensitive on the USB connection (to the point I now download the print to a memory card and print from that) and a USB CNC controller which I haven't had a problem with but there are dire warnings on the website about using a good quality cable - see https://www.youtube.com/watch?v=NUu9xwDfJ9k

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Looking at a USB cable, it appears to use ground, power, and data in and data out. So, single-ended connections. Typical Ethernet connections use twisted-pair and, presumably, differential signalling. That suggests that Ethernet, at a hardware level, should be intrinsically more noise-resistant (although my own 3D printer has run for many, many hours over USB without any problem, although that is in a domestic environment without machine tools and EMI generators nearby). I think FatFreddie has it right with reference to TCP, though. A typical USB connection will be using an application-specific protocol that assumes a reliable connection (I know my 3D printer does this as I've looked at the code) so any data corruption or loss will be catastrophic, where the TCP protocol gives a highly reliable connection; any packet loss or corruption short of losing the whole connection will be detected and corrected by resending packets. Ethernet-connected motion controllers appear to use IP as they need network addresses and I presume they also use TCP over this - why shouldn't they? So, an error-correcting protocol over a more noise-resistant hardware connection gives so much more safety margin than a simple protocol over less-protected hardware. Be interesting to see the Ethernet-level error counts in a noisy environment, though.
What you are losing, of course, is any claim to a real-time protocol, but as the network connection is being used to transfer, typically, high-level movement instructions which can be easily buffered, by buffering a couple of seconds'worth of data you can still withstand a short loss of communication during a noise burst, the TCP stuff does its job and makes sure the data gets there eventually, and the pulse generator bit of the motion controller chunters away happily working from buffered data.
Conclusion - theorist meets practical experience, shakes hands, and goes off for a pint...
Personally, I like learning from experience, and preferably someone else's experience 'cos that costs me less! But trying to relate that back to theory might give a bit more insight sometimes and lead to a better understanding and maybe a way to move forward. Cathedral builders used experience to create magnificent buildings but theory and better understanding of materials gives us skyscrapers. If that is an advance...

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Originally Posted by Neale

Looking at a USB cable, it appears to use ground, power, and data in and data out. So, single-ended connections. Typical Ethernet connections use twisted-pair and, presumably, differential signalling. That suggests that Ethernet, at a hardware level, should be intrinsically more noise-resistant (although my own 3D printer has run for many, many hours over USB without any problem, although that is in a domestic environment without machine tools and EMI generators nearby). I think FatFreddie has it right with reference to TCP, though. A typical USB connection will be using an application-specific protocol that assumes a reliable connection (I know my 3D printer does this as I've looked at the code) so any data corruption or loss will be catastrophic, where the TCP protocol gives a highly reliable connection; any packet loss or corruption short of losing the whole connection will be detected and corrected by resending packets. Ethernet-connected motion controllers appear to use IP as they need network addresses and I presume they also use TCP over this - why shouldn't they? So, an error-correcting protocol over a more noise-resistant hardware connection gives so much more safety margin than a simple protocol over less-protected hardware. Be interesting to see the Ethernet-level error counts in a noisy environment, though.
What you are losing, of course, is any claim to a real-time protocol, but as the network connection is being used to transfer, typically, high-level movement instructions which can be easily buffered, by buffering a couple of seconds'worth of data you can still withstand a short loss of communication during a noise burst, the TCP stuff does its job and makes sure the data gets there eventually, and the pulse generator bit of the motion controller chunters away happily working from buffered data.
Conclusion - theorist meets practical experience, shakes hands, and goes off for a pint...
Personally, I like learning from experience, and preferably someone else's experience 'cos that costs me less! But trying to relate that back to theory might give a bit more insight sometimes and lead to a better understanding and maybe a way to move forward. Cathedral builders used experience to create magnificent buildings but theory and better understanding of materials gives us skyscrapers. If that is an advance...

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Really well said Neale.

There is also the cable length issue with USB (just saying):whistle: ..Clive

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Originally Posted by Neale

Cathedral builders used experience to create magnificent buildings but theory and better understanding of materials gives us skyscrapers. If that is an advance...

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Yes very well said but just one small detail.? . . . Those Skyscrapers where built by Master builders with years of experience.! Those builders would not use inferior products and therefore make sure those products where well tested by people experienced in testing material Theory.!!

Theory and Experience work together for advancement but experience "TESTING" ultimately Wins and as the final say on what works and what doesn't.!!!

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Originally Posted by JAZZCNC

Theory and Experience work together for advancement but experience ultimately Wins and as the final say on what works and what doesn't.!!!

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I'm not sure that I agree with that (I think that testing has the ultimate say) but that statement is only based on my experience and there's no theory to back it up...

Would it be too presumptious that on a forum called mycncuk (which has a "mylittlepony" vibe to the name!), that most are hobbyists? In other words, not everyone wants to go to the far end of a fart over 'ethernet vs USB' (which would need a forum called IusemyCNCmachinetomillindustrialhardenedsteel.co.u k - which granted isn't as catchy)

I'm a dabbler (I use my CNC to make pcbs) & I was pleased to see the back of Mach3 ...putting on those retro stick-on Bradley Wiggen-esque sidebruns & a pair of massive Lionel Blairs just to do a CNC session was a bit much. It was therefore like a breath of fresh air to migrate to cnc-usb, which uses erhm USB ....& I've not had one bit of bother with it. For the sake of balance, that's not to say others haven't has problems, which prompted the owner of cnc-usb to illustrate what a difference the actual usb cable can make...

https://www.youtube.com/watch?v=NUu9xwDfJ9k

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Originally Posted by Neale

I'm not sure that I agree with that (I think that testing has the ultimate say) but that statement is only based on my experience and there's no theory to back it up...

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Ok I'll amend it to what was meant and say Ultimately Experience testing wins.!!. . .:smiley_simmons:

My god i must be doing everything badly.. cheap ass 5m usb cable coiled up, wrapped around extension leads and all sorts and running off a laptop. I must be very lucky.

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Originally Posted by JAZZCNC

Ok I'll amend it to what was meant and say Ultimately Experience testing wins.!!. . .:smiley_simmons:

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I wasn't being very serious! My personal problem is that anytime someone talks about the value of experience, it reminds me of my father whose attitude was along the lines of, "That's the way I've always done it, so that's the way it has to be done!" Didn't leave him much room for improving anything... I cheerfully admit to stealing the results of other people's experience where they've been kind enough to publish it - which is why I have a CSMIO-IP/M waiting to be installed, complete with Ethernet connection and 24V differential signalling.

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Originally Posted by JON

My god i must be doing everything badly.. cheap ass 5m usb cable coiled up, wrapped around extension leads and all sorts and running off a laptop. I must be very lucky.

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FatFreddie said he had so many problems with USB and his 3D printer that he gave up using USB. I've been using USB with my 3D printer for more than 3 years now and I've never had a problem with it. There's nothing wrong in principle, it's just that the safety margins with respect to noise are much lower than with Ethernet. There are also issues if you rely on the 5V supplied via the USB port as this can be a bit flaky as well. My printer controller has a separate supply - maybe that's why mine is more successful? Don't know but it's a case where experience gives different answers depending on who you ask.

As for theory versus experience - I use Ethernet-over-mains to get a network connection to my garage as the layout of my house makes the wifi signal a bit flaky out there. That signal goes through two ring mains, 3 MCBs, and an RCD. I wouldn't expect anything to get through that lot (based on the principles of high-frequency signals getting through a bunch of inductors), but I tried it, it works, and it's really useful for moving Gcode files around and that kind of thing. Stops working as soon as I turn on the router control box and VFD, though!

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Originally Posted by Neale

I wasn't being very serious!

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Yes I knew that neil, I wasn't exactly being too serious my self.! . . . And regards your Father experience then I fully it get it.!
To me it comes close or equal to "Can't teach Old Dog new tricks" in terms of irritation.! . . . .I'm so far removed from both it gets me in trouble at times But Experience applied with intelligence along with a good dose of common sense win every time over theory alone in my book.! . . . . But . . . . All my best ideas and achievements started with " In theory it should work" but it does take certain amount of experience to allow the theory to evolve.!! . . . .Chicken and Egg maybe.?

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Originally Posted by JAZZCNC

Yes I knew that neil, I wasn't exactly being too serious my self.! . . . And regards your Father experience then I fully it get it.!
To me it comes close or equal to "Can't teach Old Dog new tricks" in terms of irritation.! . . . .I'm so far removed from both it gets me in trouble at times But Experience applied with intelligence along with a good dose of common sense win every time over theory alone in my book.! . . . . But . . . . All my best ideas and achievements started with " In theory it should work" but it does take certain amount of experience to allow the theory to evolve.!! . . . .Chicken and Egg maybe.?

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Sadly I learned long ago that "common sense" is not so common!!! G.

Hi all,

Wow, this has been an interesting thread to read, I feel like I turned up a few years late and more dollars short. For anyone still reading this thread, I'm sure parallel, USB, and ethernet all have a role to play. I have found that USB is problematic in some cases, particularly with Stratasys industrial grade 3D printers, while ethernet works really well. On a CNC mill I had to maintain in a previous job, the reverse was true. In managing some laboratory instruments with stepper-driven actuators, parallel was the only choice because the instrument was made in 1987, and to "upgrade" to USB would cost the business over $80K USD... so we said "Windows 3.1, a parallel port, and some floppies are good enough for us thanks".

I get that people want to express their experiences (who doesn't). I'm glad that each person here has a favourite. For me, building my first DIY CNC, I have chosen ethernet because it suits my situation. I'll be really intrigued to see how a Mesa 7I76E card goes. How that will play out... who knows. If it fails miserably, I have a dozen old computers laying about, the ability to crimp and test my own crossover cables, and a lot of networking experience. If all that fails, I have a USB Mach 3 card that I was given.... for reasons I will never understand.... when I was buying some shielded spindle cable. They sent the USB controller instead. When I contacted the seller, they sent me the cable I originally ordered and told me to keep the card.... <insert confused face and shrug here>.

Anyway, thanks to all who have shared their views on the subject, but at the end of the day, we each must choose our own path. I'll let people know how my ethernet controller works out... but it'll take a while.

Take care everyone!
Hamish.

A blast from the past.

USB has improved because they have moved the parts that wear out away from the PCB and onto the cable so they are dead easy to replace.

Ethernet is delightful, how could anyone disagree with four twisted pairs in a ready-made, cheap as chips, cable? :tickled_pink: