Wiring Advice linear scales

[electromech31]

Been working on and off on my mill for several months now as time and money allows.
It started as a Tri-Onics Handyman mill, stepper drive, Variable head. linear scales, ballscrews. Old Tri-onics controller was shoot. Good addition to my shop.
Replaced boards with PMDX 302 breakout board and Gecko drivers, very good products. Also had to rebuild variable speed head (shim, wore shaft). I kept power supply, steppers and linear scales.
So far I have steppers running with Mach 3 (free download for now). Tested movement with 1,2,3 block clamped to table, zeroed indicator, ran a loop program, moved 6" square both dirrections. Kept "0", was very suprised for the age of the mill.
Here is where im at know, I want to hook up linear scales to give me a Digital readout when I want to run in as a manual (yes I want run it as a manual). I have already looked up about close looping Mach 3. I need info on hooking up the linear scales.
+5 Vdc, A, B and common.
Do I need a board in between scales and computer LPT2 (I already installed extra parllel part)? Or can I hook them up to the parelllel directly????????

[electromech31]

Pmdx bob, gecko and power supply

[electromech31]

I did find a Site where someone used rotaty encoder and use a Dos program for their DRO. But I was looking at using this info but the pins looked wrong. From what I have read parellel part input pins are 10, 11, 12, 13, and 15, Schematic show 2,3,4,5,6,7. SO what am I missing??????????
http://www.lindsayengraving.com/othe...rests/dro.html

[electromech31]

hello hello is this thing on????? I posted this days ago.
I searched this forum for advice on Linear scales.
I have a simply question on what are my choices, Do I have to purchase another card to use linear scales OR can I hook them up directly to a second parellel port?

[thebodger@roger]

From what little I know about Mach3, you can't "close the loop" with direct feedback. With EMC2 and a PICO or MESA card it is possible. EMC2 runs under Linux OS, not Windows, but it's free download. It would be best to ask this type of question in the Mach forums. You stand a better chance of getting the answers to what you ask.

[electromech31]

I realize that Mach 3 can not give a closed loop feedback. This was not my question it was HOW to hook up the linear scales, wither with a board or directly to the parrellel poart.

[thebodger@roger]

A few things that you need to find out. What is the scale output ? TTL 5 volt, or 1VPP sinewave, or what? When you find out that will tell you if an interface of some type is needed. Also what DRO software are you going to use? I would think the DRO software will determine what pins to use, because the P-port pins are bi-directional, so what pins does the software read as inputs?

[Al_The_Man]

I found with the Lindsay site DRO you do not need the buffer transistors, this uses a PP so you may be able to.
Unfortunately as the Bodger says, without knowing the exact type of output of the scales you have, it is impossible to say for sure, open collector, RS420 etc?.
All I can tell you is I tested the Linday PP version with an differential encoder directly and had good results.
Al.

[electromech31]

It is a 5VDC, A, B channel.

[Al_The_Man]

Unfortunately that does not give the whole story, at least they are not low level sine wave, It is just a case of trying it and see if it works unbuffered, or without a pull up resistor.
There is a good chance they will.
Pins 2~9 are the bi-directional data port, so it is being used to input the encoder signal.
Try them with the Lindsay s/w and run that when you want to run manual if they work.
Al.

[electromech31]

Thanks Al the man. Thats what I was looking for. Pins between the Lindsay and Mach was throwing me for a loop. Ill let you know how it works.