Re: Pixie error connection

Jim,

I think there are 2 ways to handle the problem. What I was trying to
do was just put a switch on the negative side of the estop wiring to
open the circuit and trigger the estop. What I think you have
suggested is to directly control the estop relay itself which
eliminates the need for another relay? The problem is whether the
open collector error line of the Pixie board will do its job and not
just go to 0v to trigger a false error condition. That is what is
happening now with the relay I am using. Everyone here was trying
to figure out how to get the relay I have inserted in the circuit to
trigger by the Pixie. Your way seems simpler with one less
component.

Thanks
Keith

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "James Cullins"
<james_cullins@...> wrote:

>
> Tom , Keith,
> I believe Keith is using the Sound Logic breakout boad.
> So unless I am not understanding what you are trying to do This is

what I would do.

> Ehe Estop terminals on the breakout board is the coil of a 5v

relay that needs to be held on ( open gives ESTOP condition ), so
all he really needs

> is the ULN2803 to turn the relay on. The ULN2803 has the diode for

the coil built in. It requires no external power.

> The 5k pull up is more that enough to drive the chip.
> Keith, I will send you a drawing as to how to wire it up.
> Jim
>
>
> On 7/16/2007 1:26:30 AM, Tom Hubin (thubin@...) wrote:
> > Hello Keith,
> > Hello Keith,
> >
> > I looked at the Pixie specs at
> > http://www.skyko.com/datasheets/SKY-P100.pdf . The paragraph on

errors

> > says that the error signal is pulled up to +5v with a 5kohm

resistor. It

> > does not mention current specifically but I can make some good

guesses.

> >
> > A 5kohm resistor to +5v can source 1ma.
> >
> > The spec says that multiple Pixie errors can be wired together.

This

> > means that the open collector at any one of the error pins must

be able

> > to sink the total current from all of the error pullup

resistors. I

> > don't know how many Pixie boards are permitted but I would guess

that a

> > six axis machine is not out of the question. That would mean

that the

> > open collector should sink at least 6ma.
> >
> > As for the relay, I only found data on the Dayton 5Z950 solid

state

> > relay at the Grainger website. Is that a Grainger house brand?
> >
> > The Grainger spec gives voltage range for the control input but

gives no

> > info on control current or resistance. So I have no idea what

current is

> > needed to activate the relay. Could be a couple of ma or could

be 100ma.

> > Gotta get the info from the vendor or the manufacturer or you

need to

> > test it yourself.
> >
>
> [Non-text portions of this message have been removed]
>