[raychar1234]

Hello everybody,

I made an external circuit, it delivers high or low voltages (+5V, 0V) through a breakout board. Breakout board can use computer's +5V on USB port. I want this signal can be input through one of pins of parallel port to computer. The purpose is to, by external signal, to pause and resume the program during the running the cutting/millng program in Mach3.

Can anyone advise if Mach3 have this function and how to configure and make connection.

Thanks in advance.

[keebler303]

Read the manual (RTFM). It is there.

Matt

[raychar1234]

Hello,

-could you explain the meaing RTFM?
-Manual mentions input #4 for external push button for single step function, this is different from that I need..

[keebler303]

-Google
-Search: http://www.cnczone.com/forums/mach_m...rt_button.html

[raychar1234]

Thanks for the directions, seems understand and need to try...

1) it seems that I can't use only one pin, that is the pin's voltage at high or low to direct it as pause and start. Instead, I need to pick two input pins to do it respectively.

2) In the OEM code list 1002; Rewind. It is quite new and interesting for me, I think its function is to reverse backward to previous line in the program from current line. Want to know how many lines it can rewind? Can it be specified?

Sorry for a newbie of me to ask so many..

[keebler303]

1) Correct, 1 pin per signal. Start is a signal, stop is another.
2) Rewind is like a VHS tape, it rewinds to the beginning. Say you started a part and the tool broke and destroyed your part, now you want to rewind and start again with a new one.

Matt

[raychar1234]

Hello,

It was tested and functioned, however, it is not satified in my use as:

- the response is too slow, almost 2 seconds delay. In my design, an external electronic circuit will send out a electrical signal, the purpose is to use it to control machine via Mach3 to precisely pause at the position at the time I press the button and restart when this button (or another button) press then. It is not for changing tools purpose, but for machining work uses which frequently need to be paused and started.

- the signal needs to be a pulse, it does not like what I expect...bringing the pin's voltage low (active low), like the limit switchs.

Is there any other method that can help?

Thanks in advance.

[keebler303]

The feedhold (if that is what you are using) does not stop immediately, but rather it initiates an orderly stop. If you know the positions where it must pause ahead of time, why don't you just program your code to do that?

Matt

[raychar1234]

Hello,

Yes, it is feedhold(pause), cycle start also not start immediately!

The required stop and re-start positions are not pre-determinated. The external circuit monitiors machine actual machining parameters to determine when and where are they, so I can't write them in program.

Thanks,

[keebler303]

You will have to do some digging to see if you can find an instant feedhold. If you were to use something like a limit switch input, you would run the risk of your machine losing position as it is being asked to go from speed to stopped instantaneously.

Good Luck
Matt

[neilw20]

On general config page if LookAhead is too large then there will be a longer delay.
If you are feeding fast, the deceleration value will become obvious.
Best if you can program the stopping points. You won't get it accurate otherwise.

Is the delay caused by Windows?
Time

[raychar1234]

Hello,

It is 20 lines.
Even feeding is lowered, time lagging persists.
Limit switchs' responds are fast, why the responds in cycle start, pause in OEM buttons are slow and are different from Limit switchs. Are they made in same theory?

Thanks,

[neilw20]

In depth details of queuing here.
Probably deceleration needs to be faster.
If feeding is lowered then the deceleration will be increased by the same amount.
Try it with faster feed, and you will see it stops quicker.

Limits are instant abort.

[raychar1234]

Hello,

Thanks for the document information.

From page12, it quotes "Mach3 will check the inputs each 1/10 second to see if anything needs to be done once a signal triggers, but for time critical inputs such as Estop, limit ...to be done as only it can respond fast enough ("1 interrupt period" in another page).

1/10 second is too long! stepper motor turns a lot of revolution in that period.

It limited users to use the software in that way.

Thanks

[neilw20]

It is a Windows OS limitation. See the link on post #11.
EMC² would give you more control, timewise, if you have the patience to set it up.

[raychar1234]

Hello,

I originally thought it is the deficiency of Mach3, how come the software runs at polling the trigger for 1/10 second period, it is not possible to happen in nowadays ??GHz processor CPU?

I need to abort it.

I also think about EMC2, but, I need to learn from zero, construct my computer from zero, start from Linux...

Thanks,

[neilw20]

When Mach3 is driving the steppers, Windows doesn't even know anything is running!
It is all BELOW windows. Very smart software.
The more GHz you have the less impact Mach3 will have on Windows performance.
Not the other way around.
As long as Mach3 get serviced 10 times per second, the driver does all the work.
For higher performance, you might consider smoothstepper, but the 1/10th of a second can still be a problem.

Smoothstepper can clock the steppers up to 80 times faster according to the warp9 documentation.
Warp9 Tech. Design - Home of the SmoothStepper - Home

[raychar1234]

Hello,

I think Mach3 should have a function to pause and resume machine working by external connection (not only on-screen button). And, its respond speed should be same as the limit/Estop one.

I am a electronic/mechanical guy, doing electronic programming and mechaincal works, sorry that my little knowledge of Window software computer.

Thanks,

[neilw20]

A limits stop forces the driver to in effect, stall the queue and is controlled the driver, and Mach3 only gets the message after the event.
Homing and probing is controlled by the driver directly too. Windows only sees the results.
If you put lots of M01 every line in your code, and enable/disable optional stop this might stop in a more timely manner.
It will stop after the executed block, not like a pause, which tells the driver to pause, then the driver decelerates as programmed, and Mach3 just displays the results.
All Mach3 (windows side) does is put entries in the queue and displays the results of the operation.
Jogging is processed as described in the previous PDF, and responds instantly to the keys, as this is controlled by the driver. If windows sticky keys is on, windows can steal or delay the keystrokes making jogging dangerous and unreliable.
ALWAYS have windows 'sticky keys' OFF.

[samco]

I disagree with you there... The pause function should not act like an estop or limit switch. It should stop as fast as it can without losing position. (controled stop) linuxcnc does this. I have a switch on my control panel that is a feed hold. When I hit it - the machine stops as fast as it can while obeying the machine velocity/acceleration. (so it is pretty quick)

Estop and limit switches should be hardware and instantanious. (killing power to drives and such)

sam

Hello,

I think Mach3 should have a function to pause and resume machine working by external connection (not only on-screen button). And, its respond speed should be same as the limit/Estop one.

I am a electronic/mechanical guy, doing electronic programming and mechaincal works, sorry that my little knowledge of Window software computer.

Thanks,