Can anyone really describe the ethernet connection acorn to computer?

[hackish]

I've sifted through pages of posts, but I haven't found too much on the actual ethernet link used by the acorn. It would seem that centroid wants us to direct connect without any other devices in the middle. The reason hasn't ever been clear, except maybe that they just picked some static IP addresses and opted not to do anything else.

In my case, the software is likely to run on a vmware instance with lots of power. One limitation I see is a lack of dedicated copper ethernet from the computer to the acorn. At present, it is using a 10G fibre backbone down to the machining building. I don't expect either latency or bandwidth will be a huge issue but without any actual documentation, it is hard to say if there would be a way to VLAN the ethernet connection across the fibre.

Has anyone tried something like this before? Is there any actual documentation as to the protocol used and how latency sensitive it is, or any other limitations present?

[martyscncgarage]

It will work through a switch. But the CNC PC and the Acorn have to have static IP addresses. That is not a negotiable issue.

Please explain your setup, your machine, distance between the Acorn and the CNCPC.
A lot of us are not understanding what you are trying to accomplish.

[DannyB]

I've sifted through pages of posts, but I haven't found too much on the actual ethernet link used by the acorn. It would seem that centroid wants us to direct connect without any other devices in the middle. The reason hasn't ever been clear, except maybe that they just picked some static IP addresses and opted not to do anything else.

In my case, the software is likely to run on a vmware instance with lots of power. One limitation I see is a lack of dedicated copper ethernet from the computer to the acorn. At present, it is using a 10G fibre backbone down to the machining building. I don't expect either latency or bandwidth will be a huge issue but without any actual documentation, it is hard to say if there would be a way to VLAN the ethernet connection across the fibre.

Has anyone tried something like this before? Is there any actual documentation as to the protocol used and how latency sensitive it is, or any other limitations present?

There is no magic here, it is routable if you know what you are doing

The thing that worries me in your description is not the fiber link, that will add some nanoseconds, but who cares.

However, trying to run this on a virtualized instance would scare me for latency (not power) reasons.
VMWare has a paper on how to optimize for latency sensitivity (see https://www.vmware.com/content/dam/digi ... -paper.pdf)

I'd do what it says.
By default, the vmware latency over native can be 4-10x in response times, jitter, etc.

If you optimize the crap out of it, you can get it to be about 1.2-1.3x of native for most cases.

That may be okay enough

[Richards]

I tried running the Centroid software on a VM. It didn't work for me. With computer prices so low and the requirements to run Centroid software minimal, I have a dedicated PC for each of my three Acorn boards. Each computer runs an i3 CPU, a solid state disk, a hard-wired Ethernet connection just for the Acorn (and 1616 IO board through a switch), and a WiFi adapter that is ONLY turned on to download files. One machine is a NUC. The other machines are systems that I built using parts from a local supplier. Each machine cost about $350 to $500.

Just yesterday I made a parts list for one of my controllers. Without a computer, the Acorn, enclosure, drivers, stepper motors, wiring, switches, terminal blocks, fuses/circuit breakers, contactor, power supplies and misc. came to $1,683.98. The same system deleting stepper motors and drivers but adding ClearPath servos, Teknic power supplies and Teknic cables added about $1,500. It takes me about two full days to build a system. I know, I'm slow but I'd rather go slowly, checking out each connection carefully than troubleshoot sloppy work later on.

The real value to me is not how cheaply I can build a CNC controller, but how much value I get from using Centroid products when assembled in a robust enclosure using good quality components. It took me more than a full year to test out several designs on my test bench before finally putting a working system together. That's just the way that I do things. I could have run a mill or lathe directly from the test bench by simply adding a plexglass panel to protect the electronics from stray metal chips. Had I needed to get a machine up and running quickly, that's what I would have done with the expectation of revising the test bench version many times.

Most of my career was spent designing and building process control systems for Kodak profession photo printing machines. Because I was a one-man operation, I had to build systems that never failed. My goal was to never get a call from anyone anywhere in the Country telling me that they had a problem with one of my controllers. I never did. I use that same philosophy when using Centroid components.

[Nigelo]

On re-reading the OP, it seems he wants to control machine(s) remotely. I'm no expert on this but surely this is not the intended use that Centroid had in mind with the Acorn, never mind the potential danger this presents.

Alternatively, perhaps the OP wishes to control more than one machine from a single Workstation. This is something I am in the process of attempting and having considered a dual boot PC controlling 2 Acorns through a network switch, I finally settled on a much simpler 2 batch file scripts. Put simply, these batch files rename the active c:\cncm and c:\intercon folders to ***mill respectively and then the non-active router folders from ****rout to active and vice versa. Both Acorn controls and the CNCPC are connected to a single network switch.

I will only need 1 machine operating at any one time (precision mill or desktop router) and therefore both Acorns can have the same hard coded IP address, remembering to power up only one CNC control to match the Active folders to be used.

I have just ordered my second Acorn kit but need to wait until July for my router to arrive from Austria. Will be able to do a proof of concept in the meantime when the Acorn arrives next week and happy to report back on progress if that assists.

Nigel

[Muzzer]

I'm trying to imagine how the OP expects this setup to work in practice. The practicalities of jogging the machine, setting tool length offsets, homing the axes, changing tools, using (not) an MPG etc sound "interesting". Given that most of these operations require the operator to be in front of the CNC12 machine which seems to be in a different building, he's going to need very long arms or a PhD in marathon running.

You can VNC into the workshop CNC12 machine from almost anywhere, from almost any machine (Windows, Linux, iOS, MacOS etc), so remote operation and monitoring is possible once the thing is up and running a job. But running CNC12 remotely in a VM? Why? You don't need a large, expensive or powerful CNC12 machine, so any benefits are somewhat far from clear.

I'd love to know what the OP is visualising here.

[hackish]

The distance from the server room is about 100m, or 330'. When the ground thaws, I will lay the fibre and I will know what the latency is. I expect about 2-3ms round trip, so certainly no worse than an average PC.

A year or so ago I virtualized and recycled a whole gaggle of PC type hardware. Power savings alone were in the 1.5-2kw range. Backups are all done in 1 shot and the server has way more computing power than any CAD/CAM system needs. When I need to do something on the mill, I can just use a laptop to RDP to the virtual machine and it is as responsive as if every machine is a $10,000 piece of hardware. Major software upgrade fails? I can roll it back in under 10 seconds. Ultimately, it is about simplifying management of computer resources.

I'm a little surprised they opted to use a static IP as it creates a hassle for anyone who wishes to run more than one acorn. Does everyone with 3-4 acorns have separate computers for each?

[martyscncgarage]

I'm a little surprised they opted to use a static IP as it creates a hassle for anyone who wishes to run more than one acorn. Does everyone with 3-4 acorns have separate computers for each?

I spend about $250 for a CNC PC. So Yup, PC for each machine...

[Muzzer]

Well you've completely lost me there, hakish. I can only operate one machine at a time and that extends to both machine tools and PCs. Systems like CNC12 don't behave any better on a $10k machine than a $100 one, so I really can't see the benefit. If you use a small NUC, the power consumption is very modest and remoting into a VM from a laptop would rather defeat the energy saving thing surely?
Most of us value machines that are completely self contained. I could plug my machines in almost anywhere and they would work. In practice, I have mine networked, with internet, music and Fusion 360 etc but that's just added functionality. Each to his own!

[Gary Campbell]

I'm a little surprised they opted to use a static IP as it creates a hassle for anyone who wishes to run more than one acorn.

I'm not.

Does everyone with 3-4 acorns have separate computers for each?

Can't speak for everyone, but I have 5, so yes. I surely wouldn't want to wait for one machine to finish to start another. You can assume most are $10k pieces of hardware or more. I surely dont want to save a few bucks on "cheap as dirt" computers.