Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: greg on March 03, 2008, 06:35:16 PM
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??? i can not get my limits to work. unplugged from the bob they break continunity if any switch is tripped. hooked to the bob it[the bob] goes from 0 to 5volt when a switch is trippsd but the reset does not go off. i have them set to port 1 all on pin 12 all active low [have tried active high same thing]. what can be wrong?
thanks greg
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Hey Greg,
I assume you mean the Reset doesn't trip.
Are your inputs enabled ? Not clear in your post.
RC
Also, are they wired in series ?
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yes i mean the reset. yes i have them enabled. tried both active high & low. checked & unchecked emulate [not sure what this is or what it does?]. i do not know what else to try.
thanks greg :)
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Oooops,
Attempted to edit.....and lost it.
I don't think the override would keep them from working.
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??? ???anyone else have any ideas? ??? ???
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Greg, from what yu describe you should be using active high setting if th evoltage goes high when a switch is tripped. It seems as though the signal is either not getting to mach or is set for the wrong pins.
You can check to see if the signal is coming in on the port from the diagnostic screen. When you trip the switch one of the leds on the two rows of diag led should light up. If you see activity there then it is a pin selection problem.
(;-) tp
If
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on the diagnostics page none of the lights flash when i toggle a switvh. when i put the switches on active high the big error box comes up & when i tell it to fix the problem it puts it back to active low.
thanks greg ???
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How about telling the software in the " input signal" , which Pin on your driver board you use for the limit switches in series
X++, Y++ and Z-- should use the same PIN number. - if your Z axis limit is negativ. I have to check that - i`ll be back.
Adam
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i have them all on pin 12.
thanks greg ???
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Greg if you are not seeing the activity on the leds then the signal is NOT getting through your BOB. I assume that your switches are set up in series and you end up with one wire leading to an input on the BOB and one to board common ?
ALSO keep in mind that pin 12 on the BOB may not be pin 12 to mach(;-) YOu will have to consult the BOB manual for the correct pin out.
I would use normally closed set up so if a wire were to break it would trip also. It will require and active high setting in mach setup.
So if you are getting the signal to the BOB but not to mach then investigate that problem.
(;-) TP
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??? yes i am in series. using a continuity light hooked to the two wires the light is on until i trip any switch. when i go to active high the limit error box pops up & says there is an error. when i tell it to fix the error it reverts back to active low.
thanks greg ???
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Greg if you are getting the BOX then something is not right in your setup(;-) Possibly the pins are not set to what the switches are hooked to.
If you togle a switch and do not see a change of state on the Diag LED then the computer is NOT seeing the signal.
WHat BOB are you using? WHat input pin to the bob are you using?
(;-) TP
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Hello again
My Machine looks like on my drawing.
All the Limit switches uses the same Pin (11) because they are in series.
I hope it helps
Adam
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??? i know something i wrong. i have tried everything i can think of, it is a c10 from cnc4pc. there schematic shows to hook them [the switches] to pin 12 & 5 volt. i have it hooked that way. in mach inputs i have enabled checked pin 12. active low. like i said i can not put it to active high.
thanks greg ???
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Ok I have looked at the c10 board and it will require an active low the way it works. Set the limits for active low. NOW move to the diagnotic screen in mach
looking at the right side on the screen you will see several rows of leds group together in rows these are port/pin indicators . Next activate a limit switch and watch to see if one of these leds changes state if it is on it wil turn off verse versa. THat will tell IF the signal is getting from the BOB to mach.
By the way is this on a working machine?? do the axis move? and are they using the same BOB to hook to the drives??
(;-) TP
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Hi, Adam
Your use of pin 11 for all axises in incorrect, Should be Ground.
Pin 10, X--, X++, X home in series other end to Ground.
Pin 12, Y--, Y++, Y home in series other end to Ground.
Pin 13, Z--, Z++, Z home in series other end to Ground.
Hope this Helps, Chip
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There is also a jumper on the BOB to select 5v for the common or ground for the common. It needs to be 5V. You also need a separate 5v power supply to the board. Probably got that ? Then, switches in series, active LOW should work on any input pin. Even 2 thru 9 if selected with the other onboard jumper.
RC
One other thing that has not been mentioned is the Port Address.
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thanks to everyone for tryingto help. it is taken care of. i shot the damn thing.
greg
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Hmmmmm........Any salvageable parts for sale ?
Hey Greg, I just noticed in your first post you said it goes from 0 to 5V when a switch is hit...that's backwards. With 5v common, all switches closed, you would have 5v to the input. Hitting a switch would make the input go LOW. Active LOW would work.
How bad did you shoot it ?
RC
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now seriously i got it working & i do not know what fixed it. i have been fooling with the switches for 2 days.
this is a new router i have built.. every thing was working except the homes & limits. i have not tried the home switches as i have the control box laying on the machine.
only other thing to hook up is 2 relays.
this is my second machine. this one has been harder to get going than my first. i do not know at this point if i would try a third.
thanks to all. greg
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Well.......if it ever comes to mind.......FOR GOD'S SAKE WRITE IT DOWN ! :D
Glad you got it going.
RC 8)
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Hi, Adam
Your use of pin 11 for all axises in incorrect, Should be Ground.
Pin 10, X--, X++, X home in series other end to Ground.
Pin 12, Y--, Y++, Y home in series other end to Ground.
Pin 13, Z--, Z++, Z home in series other end to Ground.
Hope this Helps, Chip
Chip - do you really mean my connections are wrong? Its working fine.
All my Limit switches are on the end of each axis, in series and go to pin 11 and ground.
Maybe it works both ways, yours is just easyer and uses 3 pins - I use 4 pins.
Adam
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To put a stop to the argument -
All limit and home swtiches do, is send a signal to the computer. It makes absolutely no difference if they send a 5 volt signal or a 0v signal. The system will stiill work. Mach 3 can be configured in either way.
Neither does it make any difference if you wire all switches seperately, or in series to save pins, Mach 3 can accomodate them all.
However you do it, all you want is your table to stop when it hits a limit, or home to the same place every time when you hit home.
The only reason for saying switches should be normally connected to 0v - and then pushed open to send the signal - i.e. using the internal pull up resistor to raise the line voltage to 5 volts is for safety. Should any of the wires break, or come loose, or the switches fail, then the system will signal a limit switch open, and stop, before any other damage is caused. I don't think, in my case it would cause much bother at the speeds I travel, but some of these big fast rigs could cause a bit of damage if they didn't stop when they were supposed to.
I looked through this earlier, and couldn't understand the diagram - have you seperate switches for limit and home - it would appear so from your description. This is not necessary since one switch can double up as a limit and a home switch - the computer knows what to do, and it saves you inputs - but if it is working, don't touch it - the main thing is it is working.
You should not, now, need to touch your limits again. You can set your soft limits just inboard of your physical switches, and your table shouldn't go anywhere near them.
I must admit I found my home switches (allied with the limit switches) in a most inconvenient place, so I am now working on a laser homing device to put my table somewhere useful.
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Hi, Adam
Your " i do not know what fixed it. i have been fooling with the switches for 2 days."
There are many ways to setup Limit switches, With or without a B-o-Board.
Each Axis, It's own Pin.
Pin 10, X--, X++, X home in series other end to Ground or 5volt's, Depending on your Active Low setting in Inputs.
Pin 12, Y--, Y++, Y home in series other end to Ground or 5volt's, Depending on your Active Low setting in Inputs.
Pin 13, Z--, Z++, Z home in series other end to Ground or 5volt's, Depending on your Active Low setting in Inputs.
All in series and use one pin.
Pin 10, X--, X++, X home, Y--, Y++, Y home, Z--, Z++, Z home, All in series other end to Ground or 5volt's, Depending on your Active Low setting in Inputs.
If pin 11 is an Input, Then it sounds like you wasting it, You gust need the Gnd.
Thanks, Chip