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Connecting Pins to External Contacts - WHAT PAIR?
« on: October 04, 2017, 08:19:03 PM »
Moving along with my new plasma machine, have a question about connecting to pins.

I have three sets of external contact closures that are torch ok, torch up, and torch down.  In MACH3 I have defined these pins as 18 for torch ok, 19 for torch up, and 20 for torch down.  I have a breakout board on my parallel port.  What should be the common pin on the breakout board be that will create a logic high when the contact closes?  I have tried jumpering each pin to pin 18 but i get no LEDs lighting up in MACH.

Help?

Thanks,

Dale   
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #1 on: October 04, 2017, 08:52:22 PM »
I just realized that I will need to add an external 5 VDC power supply and switch the voltage through the contacts to the pins to create the logic high.  Duh!
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #2 on: October 05, 2017, 08:03:40 PM »
Okay, I do need some help here. 

I am trying to get pins 18, 19, and 20 to light up in MACH3.  In MACH3 I have the pins configured for torch on (18), torch up (19), and torch down (20).  I have three relays set up from external source that are wired to switch on +5 VDC when true.  What is the common pin for these three pins?  In other words, what will be the negative side for the 5 VDC? 

I have tried a couple different combos but can't get the LEDs to light up in MACH3.

Any help out there? 

Thanks, 

Dale     
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #3 on: October 05, 2017, 08:22:36 PM »
Hi,
are you using a parallel port? Where are you getting those numbers from? In a parallel port db25 plug pins 18,19 and 20
are all 0V.

If you look on the Config/Ports and Pins/Input Signals you will see that pins 10-13, 15 and 17 are available as inputs.
If you have a second parallel port you can optionally assign pin 2-9 as inputs as well. Still no mention of 18,19 or 20.

Craig
My wife left with my best friend...
     and I miss him!
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #4 on: October 05, 2017, 08:38:35 PM »
Yup, after doing some more reading I see that I need another parallel port.  18, 19, and 20 are grounds I see and only pins 10 - 13 and 15 are inputs.  Already using these for other stuff, so another port is needed. 

Thanks Craig. 
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #5 on: October 05, 2017, 09:04:32 PM »
Hi,
do you have a spare PCI slot on your mother boerad?

Need to be a little careful about getting a parallel port PCI card, not all of them work, in fact not many of them work.
I know that Moschip make an IC which complies with the original spec and works. That IC has been incorperated into
various PCI cards. When I get home I will hunt it down.  A working card should only be $10-$20.

The other alternative is an external motion controller. They are way more expensive but also have a number of advantages
which may well pay for you over a period of time.

Craig
My wife left with my best friend...
     and I miss him!
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #6 on: October 06, 2017, 05:15:59 PM »
Hmm.  I got a card today and will install tomorrow.  I paid $25 for it, hope it works.  Let me know what you would have chosen...

Thanks for the help
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #7 on: October 06, 2017, 06:41:34 PM »
Hi,
it has been sometime but I bought a cheap Chinese PCI to parallel card, probably four years ago. I had done a little research and this
card has the Moschip IC so I got it. Took a bit of shagging around downloading various drivers from the Moschip website be fore I found
one which worked but used it thereafter without problems for three years.

Upgraded to Mach4 and went to an ESS by Warp9. The card is now lying in a draw somewhere.

Craig
My wife left with my best friend...
     and I miss him!
Re: Connecting Pins to External Contacts - WHAT PAIR?
« Reply #8 on: October 06, 2017, 06:57:05 PM »
Hi,
some of the advantages I mentioned of using an external controller like an ESS is that it has three 'ports' worth of IO.
Its normal to have pins 2-9 of port 1 as outputs for your motor drivers. You can however have pins 2-9 in ports 2 &3 as inputs instead
of the more usual outputs. Thus an ESS set up this way has:

Outputs 2-9,1,14,16,17 port1
             1,14,16,17 port2
             1,14,16,17 port3
  total     20 outputs

Inputs    10-13,15 port1
              2-9,10-13,15 port2
              2-9,10-13,15 port3
  total     31 inputs

You can have quite a sophisticated machine with this number of inputs and outputs. The PoKeys E57 or U57 boast even more, some of which can be
used as analogue inputs reporting back to Mach via Modbus.

There is now quite a range of external motion controllers and the mature and seasoned manufacturers producing some very capable gear light years
ahead of the parallel port.

Craig
My wife left with my best friend...
     and I miss him!