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Author Topic: M5 and external reset function  (Read 1984 times)

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M5 and external reset function
« on: May 30, 2010, 10:50:24 PM »
Hi guys

It appears that if I hit the s/w reset button within Mach it will issues a M5 to stop the spindle however if I trigger a real estop (which is seen by Mach and also sets the reset button) it does not... Any ideas?

I am using a plugin to control the VFD (Huanyang.dll by Matty) and it functions fine in every other respect. Believe this may be a Mach issue not actually a plugin one.

I want the spindle to remain powered but stopped via Mach control as this is faster than cuttting all power and letting it freewheel.

What does hitting the reset bbutton actually do? ie commands sent/stopped etc


Cheers

Mark

Offline Hood

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Re: M5 and external reset function
« Reply #1 on: May 31, 2010, 02:45:00 AM »
I am not sure how your plugin works but really your E-Stop button should be double pole, one telling Mach there is an E-Stop situation and the other controlling a hardware E-Syop string that shuts everything down mechanically. That way you are not relying on software to stop, the Axis, Spindle etc, in an emergency.
Hood
Re: M5 and external reset function
« Reply #2 on: May 31, 2010, 03:09:53 AM »
Thanks Hood

The  wiring is fine and MAch does get an estop condition when a physical stop is hit. Not removing power from the spindle is intentional as you can "power stop" it much faster. All other movements are halted power is removed from the axis drives (which is actually an issue when the counterbalance is inactive on the Z... may need a power off brake)

I'm sure you will find much debate over what an estop should do... remove all power or render safe as fast as possible (which in this case means NOT removing power).

A perfect example is at my work where we have two types of estop on the printing press. The standard one stops the press under power as rapidly as possible the second (protected under a cap) removes all power. You must NEVER hit the second one unless its an electrical fire because if someones arm gets caught in the press and you hit this one the press inertia will really stuff the poor bugger up.

I do agree that relying on a software stop is not ideal however I have yet to find a work around to force a powered stop on these VFD's


What I'm confused over is why does Mach act differently depending on if the reset is hit on the screen versus an external estop. I'll have a chat with the guy who wrote the plugin to see if the fault lays there.

Cheers
Mark

Offline Hood

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Re: M5 and external reset function
« Reply #3 on: May 31, 2010, 03:36:58 AM »
I totally agree that removing power is not always the best solution, thats why I said  the E-Stop string "should shut things down mechanically" rather than saying it should remove power.

I am afraid I dont know the internal difference between pressing the Reset Button and Mach seeing an external E-Stop signal as all my machines behave in exactly the same manner when doing either, so I have no way of testing.
Maybe someone else will have an idea of the difference but I suspect that your plugin could be written to do as you wish.

Hood
Re: M5 and external reset function
« Reply #4 on: May 31, 2010, 04:12:10 AM »
Thanks Hood

I agree... I never trust software either! I can still stop the spindle using the keypad on the VFD so maybe i will just parallel an estop relay with this.... Nice and K.I.S.S. which is realy what you want in a safety circuit.

I tried using some of the programable inputs in this VFD in the past but they seem to be disabled if you are using comms for control. The front keyboard however is always active.

Cheers

Mark