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Author Topic: unwanted Momentary outputs using oem trigger start  (Read 4677 times)

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unwanted Momentary outputs using oem trigger start
« on: March 01, 2008, 09:55:34 AM »
I Have 3 machined running Mach 3 and they all do this.  When pressing an external start button My spindle comes on as it is suppose to, but some times I get a momentary output on output #1 It lasts for maybe .5 seconds. If I cycle the maching using the on screen start button it never dose this. I have try ed changing the pin# and the output #, ran shielded wire to my start button, and it still dose it. Here is my G code program it is very simple

M3
X -00.000 Y00.00000 Z00.00000 F550.00
M11 P4  -----> this one too will blink on for just a .1 of a second this is my machine on 
G1 X -00.010 Y00.00000 Z00.00000 F030.0
M11 P1   ------> This is the output, it turn on at the same time as the spindle and stays on .5 seconds then shuts off and then turns back on
G4 P00.34
G1 X -04.8000 Y00.00000 Z00.00000 F090.0
M10 P4
M10 P4
X -05.7000 Y00.00000 Z00.00000 F800.00
M11 P5
G4 P0.9
X -05.7500 Y00.00000 Z00.00000 F800.00
M11 P7
X -05.7600 Y00.00000 Z00.00000 F800.00
G4 P00.2
M10 P7
M10 P1
X -05.7650 Y00.00000 Z00.00000 F800.00
G4 P0.2
X -00.000 Y00.00000 Z00.00000 F800.00
M30
M30

My start button is on oem trigger #1 and set on active low..
I am using a simple brake out board and an amplification/printer port protection board,,
where have i gone wrong

thanks to all
Josh

Offline jimpinder

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Re: unwanted Momentary outputs using oem trigger start
« Reply #1 on: March 01, 2008, 10:37:38 AM »
I take it you are using a mechanical switch, in line with the start button on the Mach 3 screen.

The lines into the computer are held to 5v by weak internal pull up resistors. You say that your switch is active low - so it is closing to 0volts. The problem probably is that the internal pull up resistor is not strong enough to overcome all possible pulls to zero - including the length of you cable.

You would be better to change the Push Button from single contact to a change over switch, and have both sides wired - one side through a 100K resistor to 5volts, the other to ground. This will ensure a good 5 volts signal on your input when it is OFF.
Not me driving the engine - I'm better looking.
Re: unwanted Momentary outputs using oem trigger start
« Reply #2 on: March 01, 2008, 10:47:34 AM »
Hi Josh,
Here is what I would try.
Set Trigger to Active High and wire the Pushbutton Normaly Open. 

The way it is now, Pin high- pulled low with the button, if there is a voltage drop for any reason, it will trigger.   
Just a thought,
RC
Re: unwanted Momentary outputs using oem trigger start
« Reply #3 on: March 01, 2008, 10:48:44 AM »
Ok, I see where you are going, are you thinking it is outputting without pressing start? it only messes up when pressing Start. I am running a normaly open contact. if I was to put a 100 ohm resistor on pin 12 to ground I would end up with about 2.5v on pin 12? is this the way to go?
Re: unwanted Momentary outputs using oem trigger start
« Reply #4 on: March 01, 2008, 10:51:12 AM »
overload

I have tryed that one as well..
Re: unwanted Momentary outputs using oem trigger start
« Reply #5 on: March 01, 2008, 03:15:24 PM »
Hey Josh,
Please excuse me for misinterpreting your initial post.
I thought you were getting an inadvertent input.
My fault, sorry for any confusion I may have caused.
RC
Re: unwanted Momentary outputs using oem trigger start
« Reply #6 on: March 05, 2008, 02:35:16 PM »
for anybody reading this post,, I installed a j-pac from http://www.ultimarc.com and ran my cycle start and stop through the j-pax and have not had one issue.

thanks
Josh