[Blairfab]

I've got a probotix 4 axis kit with 280oz. motors.... Everything works like it should all except for the most important thing, my probotix relay board... I'm using pin 1 as output to my relay control, checked it with a meter before hooking it to the relay board , 5.1v. Like it should be when u click torch on.... 0v when torch off.... Looks like it should work.... But when I hook it up to the relay and click torch on, it only shows 1.3v.... Not enuff to work any relay.... I don't understand... U unhook it from the relay, click torch on, 5v.... What's going on?.. Any help is greatly appreciated..., it's bout to drive me insane.... Please, someone help me.....

[john-100]

Hi Blairfab

which breakout board do you have ?

if its a simple board with terminal blocks to connect to but no IC's to buffer the printerport outputs
I suspect your printerport can not source enough current to switch your relay board on
some computer mother boards have a very limited output from pin 1
try using another output , pin 17 for example

a link to the wiring diagram you have used will help

John

PS
the 3 relay board has 3 optoisolators with the cathodes connected to a common ground / negative terminal

the 3 inputs need to be taken up to +5V by the breakout board / printerport to switch the relays

http://www.probotix.com/manuals/RBX-1_manual.pdf



PPS

http://probotix.com/manuals/MondoStep4.2.pdf

on page 5 of the stepper driver manual the diagram shows the drivers optoisolators wired
so the optoisolator anodes are connected to a common +5V

this is ideal for direct connection to a PC printerport
as the printerport outputs can sink more current to ground than they can source current

[Blairfab]

Ok update.... I switched from pin 1. Obviously that's not gonna work.... Pin 17 is same scenario, and 16, and 14.... The only pins that have 5v on them are I think 2-6, which from best I can understand are for the spindle.?.. Cuz when I try to use the they"ll trigger the relay, but not with my torch on, off, button.... It just stays n all the time.... Never kicks out.... But this is with the plasma off, shouldn't matter tho, right? I figure if I can't make the led come on it ain't gonna matter no ways..... John, I really ain't sure if I understand what ur saying about the anodes?? Gotta remember, I'm a newb here...lol.... Gotta spell it out for the retarded kid.... I've spent numerous hours siphoning thru my configuration and I'm at a loss..... I am greatful for any and all advice..... Another late nite out n the garage.....

[john-100]

Hi Blairfab

now I've had a look at the kits
I see the PXB-2 breakout board is what I thought

Attachment 206828
Attachment 206824

you could try connecting pins 2 to 9 to the relay board inputs - they may be able to provide more current
( you may end up using pins 7,8 ,9 for the relays and pin 14 for 3rd axis direction , pins 16 ,17 for the 4 axis )
which stepper drivers do you have ?

If that doesn't work you may have to try either -

(1) adding 330 ohm pull up resistors between the relay board inputs and +5V (USB)

(2) another model of PC mother board using a different chipset

(3) using a buffered breakout board



John

PS

this picture of a 3 axis system using the ribon cables will have the relays
controlled by the signals sent to the 4th axis connector (pins 1, 8 & 9)
Attachment 206844

[Blairfab]

Ok, here goes.... I got it wired exactly like probiotix's wiring diagram..... In the ports n pins, What output #s can i use to operate my torch?.... In the spindle settings tab, in ports n pins, mach 3 tells me that the spindle uses output 1-6.... Do I use one of them or 7-20? Not really sure... Do i disable the spindle relay option, or the flood/mist relay?... Sorry, I know that prolly sounds like a stupid question.... I've read the mach 3 manual several times, n it don't say nothing about a plasma, just a spindle or mill.....

P.s. Ooh yeah, I can't use the ribbon cable cuz that "A" header is being used for my slave on x axis.... So no empty spaces to plug it in.....


One more thing.. The kit I have is here http://www.probotix.com/diagrams/4-A...ng_diagram.pdf

And this I'd the drivers...http://www.probotix.com/manuals/ProboStepVX.pdf

Here is the breakout board.... http://www.probotix.com/manuals/PBX-2_manual.htm

[john-100]

Hi Blairfab

I've had a look at the roboStepVX manual and expect you can use pins 1 , 14 , 16 or 17 as the step or direction signals

the schmitt trigger IC buffers the manual refers to is likely to be a 74HC14 IC and will need very little current from the printer port

using a plasma torch could be a problem with any limit switches connected directly to the printer port pins
for now I'll download the mach 3 manual and double check on the possible pin assignments

John

[Blairfab]

Welp, @ the moment this is the main issue... Which all goes back to my first post.... I can make it work on pin 17.... Until I hook it to any relay...... When I hook up the wire from pin 17 and turn torch on, the voltage drops to 1.75v..... Unhook the wire, and click, turn on torch, and I get 5v..... I've gotten a ss relay, which should work, but the same issue.... The ss relay requires 3vdc to activate, but my bob will only shell out 1.75v, when the wire from pin 17 is hooked up.... I don't get it..... I greatly appreciate the help john... Gonna try to call probotix in the morning n c what they tell me..... (Even tho, I'll b away from the machine) thanks a bunch.... I'll b sure to let ya kno how everything works out:tired:

[john-100]

Hi Blairfab

did you try pins 2 to 9 to control the relay ?
and if that works try using pins 1, 14 , 16 , 17 to control the stepper drivers that are no longer connected to pins 2 to 9 ?


the solid state relay will need an input current several mA to be switched on
and as your PC can't provide the 10 to 20 mA to control the relay board
you will need to use either one of the relays once you get it working
or some other circuit to buffer the printerport output

you may need to replace the breakout board with a buffered version


John

PS

its not easy to find out what current can be taken from
the printer port when its part of the PC chip set
(either the south bridge chip or super I/O chip depending on the age of the board)

the data for the IT8700F 128 -PQFP super I/O chip
I looked at provides a lot of info on the logic function but no
info current that can be taken from any pin

http://pdf.datasheetarchive.com/inde...SSA0007312.pdf

http://pdf.datasheetarchive.com/inde...DSA0087060.pdf

[Blairfab]

Hey john,
I got something goin here....I'll run it by u n tell me what u think.... I ditched the whole probotix relay.... I'm using a solid state relay... That's the only way I could get it to work.... Instead of supplying the 5v thru my bob, I got a lil, 5v power supply 2amp, I'm running 5v to it at all times, and I'm using pin 17 for the ground, set to active low, so when I click torch on I get the gnd, to activate the relay... More less I'm jus tripping the relay with the gnd instead of with the 5v my bob is havin problems putting out... U think there's any adverse affects to my bob doin it that way??? I've tried it and it works, every time.... Jus don't wanna fry my bob.... Thanks for the help

P.s. Gonna send the probotix relay back, since I got the ss relay for free @ work....lol

[john-100]

Hi Blairfab

that's OK ,
with the printer port grounding the negative relay terminal
the printer port pin sink more current to ground than it can supply when it switches high to +5V as you tried at first

what is the part number of the solid state relay are you using ?
you just need to check the input current to switch it on is 10 mA or less at 5V ( you can measure it with a multimeter)

any over load will damage the printer port and not the simple PBX-2
the PBX-2 has no semiconductors
it just enables you to connect your wires to the port

if the solid state relay is like this :-
http://www.getec.cl/pdf/reles/SSR.pdf you should be OK
(the trigger current to switch it on is 7.5 mA @ 12V - see top of page 1 )

the CNC4PC C10 breakout board looks like a simple buffered breakout board
the 74ACT245 IC's used can sink or source 24 mA
and should enable you to use the relay board if you needed to
as well as giving your printer port some protection

the Probotix RF breakout board instructions does not indicate what current the RF isolator chips can control


John

[Blairfab]

Hey, yea, it's the same relay as the link....not really sure what the name on it is, not in front of me...but I'll check and let ya kno... I'm gonna try to use the breakout I've got for now, just dropped quite a bit a money n it so I gotta see some return on it.... But as far as probotix goes, they don't give a whole lot of information (electrically) about their products....but I do greatly appreciate all the help....

P.s. When I do get ready to change electronics, I will definitely look into cnc4pc.... Heard a lot of good things about their stuff... Probotix was cheaper and seemed more newbie friendly... We'll see how it all holds up.....

Blairfab