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What are the recommendations for someone using a Gecko G540, to expand to dual parallel ports, in order to gain more Inputs? I want to be able to wire EACH limit switch on it's own circuit. (Which requires more inputs to be available, than the standard of 5 with a single parallel port). Please include brand name, model numbers, etc. with supplier contact info. Thanks!

[ger21]

PMDX sells a 2 port pci card that's modified to work with a G540.
You can use any breakout board with the second port.

[DonFrambach]

I've not done it yet, but I plan to add a SmoothStepper to my G540. The USB version will add one more parallel port, the Ethernet version will add two parallel ports. I was going to go with the USB version until I read a thread on CNCZone that indicated that the Ethernet version was more reliable because it more resistant to noise. Here's the link: http://www.cnczone.com/forums/diy-cn...er_boards.html

[Phife]

Im running the Ethernet Smoothstepper with a G540 on port 1 which leaves me with port 2 and 3 available for inputs and outputs, Works great I only have ports 1 and 2 hooked up since thats all I need. If you dont want to go with a smoothstepper then another PCI based Parallel port card for your PC like Gerry mentioned works well too.

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PMDX sells a 2 port pci card that's modified to work with a G540.
You can use any breakout board with the second port.

I am not very experienced with electronics. Can you please list the Model Name or number for the "2 Port PCI Card that's modified to work with a G540"? I went to the PMDX website, but am unsure if what I was looking at is the one which you are referring to- PMDX 108 Input, seems correct. But as I said, I am unsure. The PC I am using for the CNC is a Dell Optiplex GX260 1.8Ghz P4 processor, which has a built-in parallel port (with 5VDC support). Would the card you are referring to, be used to REPLACE the existing parallel port, or simply used as an additional parallel port? (It is the additional Inputs of a 2nd parallel port that I am after). The specific things I want to be able to do include:
1-wire EACH limit switch to it's own circuit X=2, Y=2, Z=2, A=1
2-wire up a probe system, for use with the Mach3 2010 screen set-
(which actually uses 2 probes, 1 to be placed in a variable position on the stock surface, with the other mounted in a fixed location on the table for measuring tooling length offsets)
Currently, I am using the built-in parallel port, and have the limit switches wired in series for each axis with the switches wired in Normally Open logic. I originally had them wired in Normally Closed logic, but damaged contacts on the Normally Closed side of some of my switches, made it necessary to change to the Normally Open logic circuit.

All switches are wired to a simple screw terminal strip, which is wired to the G540. The 5 inputs are completely filled, with this arrangement. Charge pump=1, Neg/Pos Z=2, Neg/Pos Y=3, Neg/Pos X=4, Home A=5. This leaves no room for connecting additional inputs to the G540. So, I am aware that an additional Breakout Board of some type will be needed, (in addition to the 2nd parallel port). The thing I am confused about, is how to actually wire things to take advantage of the additional inputs (and still be able to wire them into the G540).

[crob09]

I am not very experienced with electronics. Can you please list the Model Name or number for the "2 Port PCI Card that's modified to work with a G540"? I went to the PMDX website, but am unsure if what I was looking at is the one which you are referring to- PMDX 108 Input, seems correct. But as I said, I am unsure. The PC I am using for the CNC is a Dell Optiplex GX260 1.8Ghz P4 processor, which has a built-in parallel port (with 5VDC support). Would the card you are referring to, be used to REPLACE the existing parallel port, or simply used as an additional parallel port? (It is the additional Inputs of a 2nd parallel port that I am after). The specific things I want to be able to do include:
1-wire EACH limit switch to it's own circuit X=2, Y=2, Z=2, A=1
2-wire up a probe system, for use with the Mach3 2010 screen set-
(which actually uses 2 probes, 1 to be placed in a variable position on the stock surface, with the other mounted in a fixed location on the table for measuring tooling length offsets)
Currently, I am using the built-in parallel port, and have the limit switches wired in series for each axis with the switches wired in Normally Open logic. I originally had them wired in Normally Closed logic, but damaged contacts on the Normally Closed side of some of my switches, made it necessary to change to the Normally Open logic circuit.

All switches are wired to a simple screw terminal strip, which is wired to the G540. The 5 inputs are completely filled, with this arrangement. Charge pump=1, Neg/Pos Z=2, Neg/Pos Y=3, Neg/Pos X=4, Home A=5. This leaves no room for connecting additional inputs to the G540. So, I am aware that an additional Breakout Board of some type will be needed, (in addition to the 2nd parallel port). The thing I am confused about, is how to actually wire things to take advantage of the additional inputs (and still be able to wire them into the G540).

Why not just use a micro?
If your concerned about noise something like Arduino will work great, you can even find Arduino boards with alternative interfaces.
I don't think the PCI card is the way to go if you already have a DB25 port, you may also want to look into utilising the COM port if a Micro is not the way you want to go.
For the USB all you would need to do is write a plugin (Post) using the CAM programs API, (depending on the CAM program) that sends packets to the Micro, the micro would be pre-loaded with a HEX file that takes the data packets and does whatever you asked of it.
For the COM port, you would treat it the same way you do a DB25 port.
Arduino will show as a COM connection because of the TFID IC.
Most machines only use one I/O for all the limits, when one is tripped the machine shuts down until the error is corrected.

Rob
what is a cnc

[DonFrambach]

Currently, I am using the built-in parallel port, and have the limit switches wired in series for each axis with the switches wired in Normally Open logic. I originally had them wired in Normally Closed logic, but damaged contacts on the Normally Closed side of some of my switches, made it necessary to change to the Normally Open logic circuit.

If you want to use your limit switches in normally open logic, you need to connect them in parallel not series to one input of your G540.

Most people use limit switches in normally closed logic connected in series so that a switch failure will also trigger a fault.

Can you replace your damaged switches? Seems simplier than reconfiguring your whole system AND your system will be set up in a way that a limit switch failure will trigger a fault (much safer!)

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If you want to use your limit switches in normally open logic, you need to connect them in parallel not series to one input of your G540.

Most people use limit switches in normally closed logic connected in series so that a switch failure will also trigger a fault.

Can you replace your damaged switches? Seems simplier than reconfiguring your whole system AND your system will be set up in a way that a limit switch failure will trigger a fault (much safer!)

Don,
You are correct, in the suggestion for parallel circuit on the Normally Open logic. It has been awhile back, when I made this change, but the logic is currently wired as a series-parallel circuit. (I.E. the switches are all wired in parallel to the screw terminal strip, while the other side of the screw terminal strip is wired in series with the G540 input terminals). For each axis of my machine XYZ and A.
It is the desire to wire things (with the additional inputs possible with a 2nd parallel port), so that Mach can be set up to properly identify WHICH switch was triggered, as well as the need for the additional inputs for the Probes I wish to add for the Mach3 2010 screen set (auto tool zero function). I am just lost, as to how to accomplish the proper wiring scheme between the G540, and the additional inputs of a 2nd parallel port.
A Break out Board of some type, would also be needed (I assume) to allow the connection for the additional inputs. But then, how to interface the BOB with the G540 is the point where I am confused.
As I understand it, my screw-terminal strip is essentially performing the function of a BOB (to allow muliple limit switches to be connected to the single-circuit design of the G540 input terminals). Hence, the series-parallel circuit arrangement of my current limit switches. BUT no matter how you slice it, 5 inputs is all there is on the G540.
Would the 2nd BOB perform this function? I saw a board on the PMDX website that allows for up to 8 inputs when used with a 2nd parallel port. However, there does not seem to be any PDF available to ascertain whether this board could be used in my situation. (I.E. would this input board ADD 8 input capability thru Mach3's Ports and Pins?) Any help in clarification would be appreciated.

[ger21]

I am not very experienced with electronics. Can you please list the Model Name or number for the "2 Port PCI Card that's modified to work with a G540"? I went to the PMDX website, but am unsure if what I was looking at is the one which you are referring to- PMDX 108 Input, seems correct. But as I said, I am unsure. The PC I am using for the CNC is a Dell Optiplex GX260 1.8Ghz P4 processor, which has a built-in parallel port (with 5VDC support). Would the card you are referring to, be used to REPLACE the existing parallel port, or simply used as an additional parallel port?

PMDX.COM - Products for CNC and motion control applications

This will add an additional parallel port. It does have two ports though, so you can disable the motherboard port if you wanted to and replace it with these two.

For the second port, you'll want to use a breakout board. This is an inexpensive one from CNC4PC.
CNC4PC

[ger21]

Why not just use a micro?

Why, when you can just add a parallel port? And not have to program anything?

I don't think the PCI card is the way to go if you already have a DB25 port, you may also want to look into utilising the COM port if a Micro is not the way you want to go.

Why, the PCI card is the easiest way to add more I/O.
And you can't use a serial port (COM) for I/O with Mach3

For the USB all you would need to do is write a plugin (Post) using the CAM programs API, (depending on the CAM program) that sends packets to the Micro, the micro would be pre-loaded with a HEX file that takes the data packets and does whatever you asked of it.

Hmmm. Plug in a parallel port, or learn C and write a plugin to use a USB port??? Which is easier?

Why don't you write us a USB plugin if it's so easy.

For the COM port, you would treat it the same way you do a DB25 port.

No, it's 100% completely different, and a COM port won't work.

[DonFrambach]

Don,
You are correct, in the suggestion for parallel circuit on the Normally Open logic. It has been awhile back, when I made this change, but the logic is currently wired as a series-parallel circuit. (I.E. the switches are all wired in parallel to the screw terminal strip, while the other side of the screw terminal strip is wired in series with the G540 input terminals). For each axis of my machine XYZ and A.
It is the desire to wire things (with the additional inputs possible with a 2nd parallel port), so that Mach can be set up to properly identify WHICH switch was triggered, as well as the need for the additional inputs for the Probes I wish to add for the Mach3 2010 screen set (auto tool zero function). I am just lost, as to how to accomplish the proper wiring scheme between the G540, and the additional inputs of a 2nd parallel port.
A Break out Board of some type, would also be needed (I assume) to allow the connection for the additional inputs. But then, how to interface the BOB with the G540 is the point where I am confused.
As I understand it, my screw-terminal strip is essentially performing the function of a BOB (to allow muliple limit switches to be connected to the single-circuit design of the G540 input terminals). Hence, the series-parallel circuit arrangement of my current limit switches. BUT no matter how you slice it, 5 inputs is all there is on the G540.
Would the 2nd BOB perform this function? I saw a board on the PMDX website that allows for up to 8 inputs when used with a 2nd parallel port. However, there does not seem to be any PDF available to ascertain whether this board could be used in my situation. (I.E. would this input board ADD 8 input capability thru Mach3's Ports and Pins?) Any help in clarification would be appreciated.

I am not an expert and have never added any more inputs than those available with the G540 so take this with a grain of salt. I think that you need a breakout board to protect your computer from errant voltages that could be developed by your system. So, if you decide to get a two parallel port card, I think you attach the G540 to one port and a breakout board to the other. You then instruct Mach 3 to recognize which is which and that will get you the inputs (and outputs) that you need.

For what it's worth, I'm going to incorporate an ethernet SmoothStepper into my system to better control my steppers. I have ordered this breakout board to connect to one of the two extra ports the ethernet SmoothStepper provides: http://www.homanndesigns.com/store/i...products_id=59 I plan to incorporate this breakout board in my control box for features that I have not yet identified. I really have no plans at this point to use the inputs and outputs from the second parallel because I am currently quite happy using only one input from the G540 for all of my limit switches. I use the two outputs from the G540 to turn my spindle and vacuum on and off.

Don