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Author Topic: setting up a reflective object sensor for dummy's  (Read 27045 times)

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Re: setting up a reflective object sensor for dummy's
« Reply #90 on: February 06, 2008, 08:48:55 AM »
And the moment we have all been waiting for.  "IT WORKS". so I guess that terminal is used for an encoder of some kind. but regardless it must go directly to pin 15 without going through all the opto's. The discrepancy with the PDF is that there are 2 different versions of the board so if you look at the older pdf it doesn't match up to the newer board. Perhaps I should have asked Bob sooner. I guess It's something to keep in your back pocket for any future rookies who come through here with the same problem. Thanks for all your help. This has been a learning experience for all. But, Im sure Ill have another problem soon enough.  ;D
Chris
« Last Edit: February 06, 2008, 08:51:06 AM by guynamedbathgate »
Re: setting up a reflective object sensor for dummy's
« Reply #91 on: February 06, 2008, 09:16:05 AM »
Here is what Jim Cullins said about why it wasn't working for all who are interested.

"the board  has a signal condition circuit.  The ourt put is connected directly to the port pin on opto isolatiion. You don't need isloation as the circuit is never connected to any other external circuit just be careful how you route the wiring, keep away from high noise wiring like the motor wires, or use a shielded cable. The opto isolators on the board are too slow to pass the signal they are designed to filter noise on the limit/home inputs."

Chris

Offline Hood

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Re: setting up a reflective object sensor for dummy's
« Reply #92 on: February 06, 2008, 11:21:16 AM »
Thats great news :)
Maybe it would be a good idea for Bob/Jim to say that in theior manual?
Hood

Offline Chip

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Re: setting up a reflective object sensor for dummy's
« Reply #93 on: February 06, 2008, 02:54:11 PM »
Hi, Chris

Glad you got it working.

Just make sure the input is not more than 5 volts to the port.

Thanks, Chip

Offline jimpinder

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Re: setting up a reflective object sensor for dummy's
« Reply #94 on: February 08, 2008, 11:59:05 AM »
Have we finally got this working ???
Not me driving the engine - I'm better looking.
Re: setting up a reflective object sensor for dummy's
« Reply #95 on: February 12, 2008, 11:55:38 PM »
Did you resolve this by using J20? Can you explain what you did as I,m sure
this might be what I am experiencing with my machine.My actual speed DRO
is going crazy .I have a bob campbell  board and a cnc4pc index pulse card.
My disk is about 3.5" and my slot is 1/2 in width.All my wires are sheilded.
The output on the scope shows a nice pulse right up to 3600 rpm , max speed.

Offline Chip

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Re: setting up a reflective object sensor for dummy's
« Reply #96 on: February 13, 2008, 02:33:28 AM »
Hi, Glen

Yes, He got it working, This is the topic i was talking about on your original post.

Chip

Offline jimpinder

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Re: setting up a reflective object sensor for dummy's
« Reply #97 on: February 13, 2008, 03:51:36 AM »
keithmech

I think the long and the short of this was that the various opto-isolation bits and pieces on the breakout board were destroying the signal from the speed sensor.

As I said fairly early on in this post, the signal from your speed sensor - providing it is NOT above 5 volts - and if you have a scope, you can check this - should be fed DIRECTLY back to your computer via one of the input pins. Mine is and works perfectly - but then I don't have this fancy Campbell break out board, all my signals go directly back to the computer.

Jim
Not me driving the engine - I'm better looking.
Re: setting up a reflective object sensor for dummy's
« Reply #98 on: September 19, 2008, 09:11:52 PM »
I know this is a slightly old thread, but I just wanted to mention a problem I had when I set up my spindle index. This was a fresh and clean Mach3 install and I used a typical optical interrupter switch (LED and phototransistor in slotted package - Fairchild H21A1 available from Digikey) and disc on my lathe spindle. When I first tried it out I would get good readings from very low rpm to around 1000rpm and then, while still increasing the spindle speed the rpm reading in Mach would suddenly drop by roughly (very roughly) one half. I eventually found the problem and it was this: The default debouce setting for the index pulse input in Mach (in General Configuration) was set to a rather large number (it was in hundreds) and this setting is multiplied by 40uS, so I set it down to 2 (making it 80uS) and the rpm readings are now true for my full range of up to about 2800 rpm.
« Last Edit: September 19, 2008, 09:17:04 PM by TetraLite »
-Mark