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Mach 3 outputs and e stop behavior
« on: February 08, 2018, 05:45:18 PM »
Hello,

As has been noted in other threads i found from searching the forum, the output signals get set to their  inactive state when the mach 3 program is in estop.

My situation:
I am trying to use the outputs currently to control an electronic vise holding the work piece. The vise is activated by a relay driven by an output pin on my controller card. The pin is mapped to an output signal in the mach3 ports and pins setup.

My issue:
So the issue is that if the vise is closed and you e stop, it will open, which i don't want. What i want is just that the state of the output is unchanged at an estop. ie if it is inactive and you estop, it remains inactive. if it is active and you estop, it remains active. hence this problem is not solved by simply changing the output from active high to active low etc.

So i thought maybe you could use a brain or macropump to add logic to keep the output steady during estop but does the estop state override brains?or is there some other way to achieve this perhaps?

Basically i want the output signal to latch at an estop, not change to its inactive state.

Thank you for your time.  
Re: Mach 3 outputs and e stop behavior
« Reply #1 on: February 08, 2018, 07:32:52 PM »
I did a "bit" similar with a collet closer on my lathe.
The output energized a relay - pneumatic,4 way, 2 pos. solenoid valve that opened the collet(vise).
In E-Stop, power off, lightnin' strike, whatever ... as long as there was air pressure, the collet stayed closed.
Only way to open it was if Mach was running and the output went HI.
If the output is OFF during running, it will be off at estop... no change.
The wiring of the relay NO or NC along with the active hi/lo output should do what you want.
Maybe I'm not understanding what you are meaning. (it has happened)
Russ
Re: Mach 3 outputs and e stop behavior
« Reply #2 on: February 08, 2018, 08:10:21 PM »
Hi,

Thanks for your reply. I think you might get what im saying and it does sound similar actually to what i want but in your application you  say,

"Only way to open it was if Mach was running and the output went HI."

So in your setup, if the collet is OPEN as caused by mach 3 running and dictating the output HI and you hit ESTOP, does the collet then close?


edit:
Also, since my op  i tried to make a macropump test.  The script just forces  the output to active state no matter what ( ActivateSignal( OUTPUTXX)  ). So this was to check which has precedence, estop (forcing it inactve) or charge pump (forcing it to active state). The end result is that they seem to compete actually, and the vise does a nice little polyrhythmic dance. As amusing as it was it is not what i hoped for. :P

I also found another thread i did not see originally where someone replies to  a similar question and says that estop overrides settings from brains and macropump, so this seems true at least for macropump i have not tried a brain yet. I think i will just setup an arduino or something to latch the mach3 control cards outputs when estop is active (hook up estop and output signals to the arduino as well, sit it inbeteween the mach outputs and the solenoids). I just hoped i could do it without anymore hardware but i don't see a way to get mach3 to latch so far.



« Last Edit: February 08, 2018, 08:23:12 PM by fredeflint »
Re: Mach 3 outputs and e stop behavior
« Reply #3 on: February 08, 2018, 08:33:29 PM »

"Only way to open it was if Mach was running and the output went HI."

So in your setup, if the collet is OPEN as caused by mach 3 running and dictating the output HI and you hit ESTOP, does the collet then close?


 


Yup. I could not forsee a situation where M3 would be running, the collet (vise) is open, and I'd need to hit the estop.

If you want the vise ENTIRELY independent of MACH, a simple ON/OFF switch would be the easiest, imo. Why do you need some sort of sw to control it anyway ?
Re: Mach 3 outputs and e stop behavior
« Reply #4 on: February 08, 2018, 09:15:38 PM »

Yup. I could not forsee a situation where M3 would be running, the collet (vise) is open, and I'd need to hit the estop.

right right ok and i wish this was the case for me too, since this is the easiest solution.

If you want the vise ENTIRELY independent of MACH, a simple ON/OFF switch would be the easiest, imo. Why do you need some sort of sw to control it anyway ?

Yes i agree that would be very easy but I don't want it independant of mach3 though, i want it independent of ESTOP signal.

The main goal is full automation. The vise is sort of the first step. I am cutting very often the same part, like 100's at a time so i am working on a feeder/robotic arm to feed pieces into the vise, but the vise first needs to work, so that is the step we are at now.

Originally i had bought a Modbus over etehrnet relay board which i think would avoid this since i doubt estop sends modbus coil register signals (i hope not anyways haha). But even though i could get it to work with the modbus test window in mach3, i could not get it to work with vb script or brains, even after reading some threads which sounded like people had similar issues, these solutions did not workout for me. So instead now i moved the goalpost a bit and  am going direct onto my controller card which unfortunately now seems to be affected by the estop signal, although from research this seems normal, not an issue with the card, it is what "should" happen etc...

anyways its a classic case of not doing enough research before buying some parts and just assuming it will work out, but ya im just trying to make something work with what i have on hand atm. it does almost work ahah.

here is a short video if you want to see a test of the vise opening/closing for fun.

https://www.youtube.com/watch?v=xftNNhw9QnA
Re: Mach 3 outputs and e stop behavior
« Reply #5 on: February 08, 2018, 09:37:29 PM »
Here is a thought:   2 relays
Basically, considering the voltages required...
Use 1 relay, NO, when energized by a mach output (thru bob relays ?) it closes and closes the vise.
 It also latches itself with one wire to the coil.
That latch wire goes through the NC contacts of another relay. The coil of this second relay goes to a second output of Mach.

Momentarily energize coil1, vise closes and latches.  Line, or vise voltages keeps it latched as long as power is on. Estop, or not.
The only thing that will open it is if mach is running, out of estop and you momentarily activate output 2 to break the latch.

The only way to close the vise is if mach is running, out of estop and out1 is momentarily activated.

I think ...
Re: Mach 3 outputs and e stop behavior
« Reply #6 on: February 08, 2018, 11:34:03 PM »
That is not a bad idea either.

It made me think also you could just get latching relays and since you just pulse them high/low to set the relay state... i will sleep on it and try something tomorrow.

Thank you for your thoughts!
Re: Mach 3 outputs and e stop behavior
« Reply #7 on: February 09, 2018, 12:15:35 AM »
Keep us posted ..............

Thanks,
Russ

Offline olf20

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Re: Mach 3 outputs and e stop behavior
« Reply #8 on: February 09, 2018, 07:15:14 AM »
Would a two (dual) coil solenoid do what you want??
olf20 / Bob
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998
Re: Mach 3 outputs and e stop behavior
« Reply #9 on: February 09, 2018, 09:00:52 AM »
A dual coil latching, set/reset relay would be a more convenient package of what was described above ..... if you have one on hand.
Thanks Bob,
Russ