Messages

5751

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 04:32:02 PM »

Hi,
I personally would not have it run automatically with Ref All but be called from a screen button or physical button.
Motion which happens automatically has the tendency to catch you out on occasion and cause a crash.

The good thing about Mach4 is that you can make it do pretty anything you want. Provided you place the code appropriately
you can have any or all of those behaviours.

Craig

5752

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 03:58:51 PM »

Hi Nick,
additionally if the code is embedded in another function the only way to get it to run is to run the function in which it
is embedded, ie Ref All.

If however you leave it in the screen load script it is visible to all parts of the GUI. Thus you could call on the GoCenter
function from a screen button, a physical button and if you want to your Ref All script could also call it. Leaving the
GoCenter() function in the screen load script offers you the maximum flexibility.

Craig

5753

Mach4 General Discussion / Re: Motion Controller recommendation

« on: December 03, 2017, 03:52:27 PM »

Hi,
that is correct, the FPGA on the previous model USB SmoothSteppers is smaller and somewhat less capable than the ESS.
Warp9 hope to release a plugin for the USB version to run Mach4 but are focused on completeing the ESS plugin.

The ESS has been on the market for some years, do you not suppose that there would have been a major backlash had
it not been capable of controlling a spindle? It does in fact control a spindle perfectly adequately, depending on the breakout
board you've selected to partner it, and is one of the most popular external motion controllers for either Mach3 or Mach4.

Craig

5754

Mach4 General Discussion / Re: Motion Controller recommendation

« on: December 03, 2017, 03:19:07 PM »

Hi,
yes it does, PWM. And PID spindle control has just been released last week.

Craig

5755

Mach4 General Discussion / Re: Motion Controller recommendation

« on: December 03, 2017, 03:07:27 PM »

Hi,
the ESS by Warp9. Still has ribbon cables to connect to standard breakout boards which are required.
been in the Mach market since there was a Mach market just like PMDX.

Craig

5756

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 02:32:53 PM »

Hi,
yes you could but I wouldn't advise it, certainly while the code is still being developed. You run the risk of grafting
faulty code into an important Mach function and possibly break Mach in a way that might be hard to fix.

I have the code in two locations. Per Daz's suggestion I have made a temp file in my profile which allows me to use
the editor for debugging.

Once I was happy enough that the code was OK I then put it into the screen load script, just before the Sig Lib
code for convenience. I stripped the  if (mc.InEditor) conditional out but otherwise the code is indentical.

Put GoCenter() as left-up script of your screen button and your'e done.

You may if all is well include a reference to the function from your Sig Lib so that a physical button can be used.

To start with just put it in the screen load script and attach the screen button. Once you've experimented with it
and proven its worth THEN consider how you might extend it and the means of utilising it.

Craig

5757

Mach4 General Discussion / Re: Creating your own homing script

« on: December 03, 2017, 04:11:34 AM »

Hi RT,
index homing is usually enacted by the motion controller. The ESS certainly is and that's what I'm familiar with.

The reason is that if Mach were monitoring the index signal there will be a delay of milliseconds at the least before it could make some sort of decision
and stop the motor. If enacted within the FPGA or DSP chip of the external controller it could respond within microseconds, this is exactly what the ESS does
and so it can very quickly detect and act on an index pulse.

Within the limitation that Mach is going to respond slowly with consequences re the accuracy of the homed position I can see several ideas that would allow
you to monitor the index pulse.

One I've had some success with is:

Code: [Select]

LUA Syntax:
rc = mc.mcSignalWait(
number mInst,
number sigId,
number waitMode,
number timeoutSecs);
This responds at the rate of the signal script, ie pretty damn quick. If I understand Machs treatment of signals then within a millsecond or so.

Another possibility is to have code within the PLC script which reads the index input. The PLC script in Mach4 runs a lot faster than the macro pump in Mach3
but would still represent a potential delay in reading an index pulse of 10milliseconds or so.

Your code does something similar, you read the index pin and if not active then sleep for 25ms and read it again. In the mean time Mach can do nothing
else. You've given it a job to do so it tries to do it...but it can only do one thing at a time. If for whatever reason it can't do the job you've given it
then Mach is said to block, and you've seen messages to that effect.

I am no Lua expert but I believe that either of the two strategies I've mentioned allow Machs GUI to run while its waiting for an index pulse. In the case of the
first API call approach if an index pulse does not ocurr within a given time it will timeout rather than block.

The broad strategy I'm proposing is:
1) Issue a motion command that allows the spindle to rotate at slow speed for at least one complete revolution. This would require a
    mc.mcCntlGcodeExecute() API call so that the function returns immediately.
2)Have a small block of code to store and manipulate the machine co-ords that would execute when the index signal came active with the mc.mcSignalWait()
    API above.
3) Abort the remainder of the move. Note I'm not sure that a clearing of the motion planner is possible in Lua, it may be restricted to C++ in a plugin.
    Should that prove to be the case then it could be worked around...just let the motion command run its course and then back up to the co-ords stored
     as a result of step 2.

Does any of that sound like it might work to you?

Craig

5758

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 02:13:40 AM »

Hi,
shows the Diagnostic/Regfile with iRegs0 expanded. The entries are the defaults, double click to overwrite.

Craig

5759

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 02:05:50 AM »

Hi,
no. The actual number substituted at runtime are the contents of the registers Xcenter, Ycenter, Zcenter.

You can see what they contain by Diagnostic/Regfile and expand iRegs0. You can edit any of the register contents by double clicking and overwriting.
Thus while the center of your table might be 10,3,0 you may decide that you want to change that to match some feature of a jig say located at 12,2.56,0,
it would be a simple matter to type those numbers into the iRegs0 entries and carry on. No need to edit code.

Craig

5760

Mach4 General Discussion / Re: Reference all home help.

« on: December 03, 2017, 01:57:37 AM »

Hi Nick,
the code is clean and ready to run. The only change was to remove the GcodeExecuteWait and substitute GcodeExecute per Daz's recommendation.

The typo comes from the fact that in the API.chm the two API calls show exactly the same syntax, ie someone who composed the .chm entry forgot
to put the 'Wait' in one API call and I didn't notice until after I'd posted.

Craig