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Offline spnar

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lpt problems
« on: September 16, 2008, 05:17:41 AM »
Hi Guys

I have set up the spindle index on input 13 port 1 and while testing found that if i leave this input high for a few seconds i get a pulse high
output from 2 , 3 and some other output. I tried input 11 which is the other available input i have with the same result.
From what i gather pin 13 is used as SELECT when this port is used for printer.I tried to change from SPP TO EPP with no success.
Can anyone tell me what is going on. ???

SPNAR

Offline jimpinder

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Re: lpt problems
« Reply #1 on: September 16, 2008, 11:40:26 PM »
There is no connection between the port and the printing software when used for Mach3. A completely different set of drivers are installed to run the port, so it is not a throw back to it's printer days.

What you seem to be saying it that you have a detector on your spindle. You have applied this to pin 13 of the LPT1 socket. I assume you have set this up on Config/Ports and Pins/Input signals as the index input. I assume you have tested the iput - i.e. it gives a good signal when not connected, and when connected, the input shows up on the diagnostics.

Does it work ?? Do you see the rev counter count when you fire up your spindle.

Are you using a BOB board, if so which one. Does this reverse the inputs. The input pins on the LPT1 are normally held high by internal resistors (so this is their normal OFF position) your input should be active low, (to the LPT1 - not necessarily to the BOB)  i.e. your detector should go to 0v to give an index signal.

I cannot see that holding the index signal high (it's normal OFF state) can give a signal OUT on other pins - these are to your stepper motors, I presume. Are these through a BOb as well.


Not me driving the engine - I'm better looking.

Offline spnar

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Re: lpt problems
« Reply #2 on: September 17, 2008, 04:42:21 AM »
I am starting to thinkthat this has nothing to do with software or drivers .
This is some switching IC in my PC acting funny.
Yes the rev counter works and the revs it shows are realistic. It is only when the signal on pin 13 is kept high for some time that i notice this
pulse.
On my pc inputs 11 and 13 are LOW from the pc.If this persists i will have to add another port and work from that.
I have checked on the net to see if there is any reason for this behavior with no luck.

Spnar :-\

Offline jimpinder

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Re: lpt problems
« Reply #3 on: September 17, 2008, 05:32:47 AM »
Pin 13 should be high when not connected to anything - Pin 11 was an inverted input so therefore may be low.

If you have to buy another card, you may consider then Smooth Stepper. This conncts to your USB input. It contains all the outputs for the axis, and also a large number of input and output lines for use with limit switches, rev counter etc.

It also has pulse generating in-built in the card, so the PC does not have to do it, meaning your PC can concentrate on the computing, leavng the Smooth Stepper to drive all the outputs.

I haven't got one myself (yet) but those who have them say the are excellent.
Not me driving the engine - I'm better looking.
Re: lpt problems
« Reply #4 on: December 06, 2008, 11:40:59 AM »
Hi Guys

found this thread while searching for a solution to a similar problem: i.e. a toggling input on pin 13 - I am using the Bob Campbell board V1.8 and am constantly getting a toggling pulse on input 13 on the diagnostics page, whether I have a switch connected to that input on the board or not - using it as an input with a remote switch to start cutting the file. I have tried 4 different computers and still get the same result. on some computers it starts toggling immediately and on others it only starts toggling once the drives are activated. - Pulling my hair out!!!

SPNAR - what board are you using?