Re: [CAD_CAM_EDM_DRO] Re: sherline motor/speed control wiring **BIT State??

Doug,
I was just looking at the port state problem on my machine as I am testing
out a pendant jog circuit (works great). When the computer is connected and
boot to CNC Pro, and the the jogs operated, the ports state is _anything_.
If I bump the jog I will eventually find a high state on the step line.
Now I can operate the pendant (in parallel).
But the direction bit may also be low, so I have to bump the
opposite keyboard jog to find a high setting.
So, it seems, the last transition is whatever, wherever it was left at end.
Clearly a 1 x 2 line selector is needed (got'em in my junk box) to isolate
the pendant from the computer.
The I/O's (no I's actually) are another matter and until a program is set to
run, it seems to be another case of anybodys guess.
I'm thinking of a logic interlock. For spindle "on" stepping bits must be active
on any axis before M04/5 will be honored, the normal "good" data case.

Rich D.

Doug Harrison wrote:

>
> ----- Original Message -----
> From: tauseef <alieron@...>
>
> > One thing I have noticed is on boot up, no matter
> > what the I/O says on CNCPro the motor is on. I think this might be a
> > cncpro problem but am unsure. I have to cycle the I/O to turn it off.
> > I have made a quick start up and shut down procedure that I follow to
> > reduce any risks to my computer, stepper board and mill.
>
> Tauseef;
> I just went to the shop and looked at the I/O on my machine. IO3 comes on
> momentarily during boot-up. IO4 then comes on and stays on until I load
> CNCpro. All IO lines are set to enable low.
>
> I've drawn a circuit that ties the e-stop to the enable pin of two 74ACT245
> tranceivers through which all data and IO lines must pass on the breakout
> board. Additionally, the e-stop circuit is tied to an enable button so the
> machine comes up with all lines disabled.
>
> The problem I have not worked out is what happens when you exit CNCpro to
> edit a program. The lines stay enabled and are thus at the mercy of
> whatever the computer decides to do with the parallel port. On my shop
> machine the bits stay low so it has not been a problem. However,
> Ctrl-Alt-Del (and some software?) may reset the port on some machines while
> leaving the tranceivers on the breakout board enabled. Bummer!
>
> I'm looking for a method of resetting the breakout board that will occur
> automatically anytime the operator exits CNCpro.
>
> Doug