G540

Ok... I have three machines running Mach3. 2 are using G540s, and the third will probably get one soon as the controller on that machine won't handle the motors I want to use (not my first hardware change over).

For the experience sake I would like to change one of my machines over to LinuxCNC. I thought I read a post where the G540 was a pull down option now in LinuxCNC, but I can't find it. (The post where it was discussed, I haven't reloaded Ubuntu/LCNC yet.)

The long and short of it I want to know if a change over is going to be a couple hours or a whole weekend?

I also saw a recent post where a user was having difficulty with the charge pump function when using G540s and changes to the LPT state. Has that been resolved?

All three of my machine controllers are currently XP Pro boxes using the on board LPT port in EPP mode, and they will all run 10-30 hour jobs as long as I don't touch the computer while they are running. (Actually 4, but the 4th one has some issues.)

I figured I would start with one machine setup as dual boot so I could check back and forth on configuration.

Yes, my CAM shows both EMC and EMC-Turn post processors.

To start with you can use the live cd to run a latency test on the computer you want to try. If it test well on a long test it may be a good candidate.
If you have working Mach set ups, the computer has good latency and you are comfortable with Linux transferring the settings over should be quite easy.
Why not start with the live cd and experiment with using LinuxCNC before you even install anything.

Is this the thread you are talking about?
www.linuxcnc.org/index.php/english/compo...ew&catid=38&id=14788

Rick G

Rick G wrote:

Is this the thread you are talking about?
www.linuxcnc.org/index.php/english/compo...ew&catid=38&id=14788

Rick G

No, but I did read that thread. A couple times now.

This was the one I was asking about.

I thought I read a post where the G540 was a pull down option now in LinuxCNC, but I can't find it. (The post where it was discussed, I haven't reloaded Ubuntu/LCNC yet.)

Doing latency testing makes sense. Time to create a new live cd.

Hi

For pull down read pull up, then you find

www.linuxcnc.org/index.php/english/compo...tid=9&id=19622#19662

That is probably what you read, the last entry from Peter Wallace refers to it.

The crux of it is that the G540 appears to need an amperage to activate the charge pump that you are not going to get from a 3.3v parport
or possibly from a 5v one in other than EPP mode

There is no 'option' as such, you would need to wire it.

It was suggested that a separate 5v source and a 470 ohm pull up be used, presumably with the parport pin operating an opto-isolated switch.
Quite a lot of BoBs now allow you to source your own supply for several pins on the board in this way, rather than use the on-board 5v current limited supply.

An example is www.diycnc.co.uk/uniportV2.pdf



If you have just soldered direct into the parport cable, well you would have to change that.
Makes sense to use a BoB, for the outage protection it gives anyway.

regards

Edit
The link I meant to post was
www.linuxcnc.org/index.php/english/compo...mit=6&start=12#14902
Obviously copied the wrong tab

After you burn the cd take a look at Stepconf which allows an easy way to create a new set up from the information you have taken from Mach.
Also take a look at the sample configs that are included with LinuxCNC.
As far as the G540 is concerned it may just work fine the way it is, just give it a try.
Let us know how you make out with the latency and the G540.


Rick G

Rick G wrote:

After you burn the cd take a look at Stepconfig which allows an easy way to create a new set up from the information you have taken from Mach.
Also take a look at the sample configs that are included with LinuxCNC.
As far as the G540 is concerned it may just work fine the way it is, just give it a try.
Let us know how you make out with the latency and the G540.


Rick G

Will do. I tried to setup EMC2 about 3.5 or 4 years ago (different controller) and didn't have a clue where to start. I installed Mach and the xml from the vendor and was up and running in less than an hour. I've learned a little bit since then and figured I should give EMC2 another try if for no other reason than the experience.

Does EMC2 (probably the wrong area to ask) multi thread? ie can it display video toolpath and process large files without flaking out? Mach can do one or the other, but not both in most cases. I have run files over a million lines of code a couple times and files of a couple hundred K are pretty common for me.

I installed Mach and the xml from the vendor and was up and running in less than an hour

If your hardware matches one of the included configurations should not even take that long to get going with LinuxCNC now that you have some experience.
If you need to create a new configuration and you know your settings from Mach, such as parallel port pin numbers, driver information, speed, acceleration, machine size, etc. run Stepconf and you can be up and running in no time.
Be sure to read the getting started section.

Rick G

Latency Test:
(I have 3 identical machines currently running onobard LPT and onboard video, but I could change those if need be.) I have some new LPT cards laying around.

I test one so far. I would expect the other two to react similarly:

Servo Thread
Max Interval 1003848
Max Jitter 7812
I did show a higher (about 25000 at one point, but I was unable to repeat it when I restarted the latency test.) I may have also read the wrong thing as I was hoping tons of windows and moving things around to try and ge the worst possible numbers.)


Base Thread
Max Interval 46006
Max Jitter 21413

Just checked. It was not set to EPP mode in the BIOS. (That machine was not connected to a G540. Its just the only one I had that wasn't running a job at the moment.)

Will retest...

As soon as a opened a couple windows it shows 25K max jitter on the servo thread. Other numbers were similar.