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1:1 wrote:
k from manual, related to Estop;

iocontrol.0.user-enable-out
(bit, out) FALSE when an internal E-Stop condition exists.

iocontrol.0.user-request-enable
(bit, out) TRUE when the user has requested that E-Stop be cleared.

iocontrol.0.emc-enable-in
(bit, in) Should be driven FALSE when an external E-Stop condition exists.

Without an external Estop the configs must connect
user-enable-out to emc-enable-in

Do you mean that if you physically connect pin 49 and 50 together it comes out of Estop?

Connecting the two I go into e-stop - the button on screen is greyed out also, indicating to me I couldn't go out of it via the UI

I expected a NC circuit (what I earlier called normally on which is correct but not the right term) - its basically an inversion of logic which I think I could fix by doing another inversion, but I just want to make sure I'm not doing a 'two wrongs make a right' situation ...

I've been bitten by those in the past with limits when operating stage/show automation as some parts of the system just look at once element of the logic and if its inverted to 'fix' another part then its blood stains on the wall

yes it easy to get lost. It depends on what is connected to the Mesa board.
I use opto22 products and between Mesa board and the opto22's I often need to invert the inputs.
If you load a halmeter in your config (add loadusr halmeter to hal file or if using AXIS its selectable)
then you can read what the pins are actually getting after all the inversions.

I might add that there is a classicladder estop program available through pncconf which may or may not
help you understand the Estop chain better. If you use AXIS it allows you to load classicladder's GUI and then you can see the estop chain evaluated through classicladder.
Just another option.

how do you have your estop connected ? your quite correct in that the estop is a closed circuit and open state when triggered , however when the estop is triggered is the pin voltage rising to above say 3.5v ( presuming a 5v power )
mesa cards are active high , so the pin must switch above a threshold for emc to accept the change of state , it may be although you open the estop the pin stays in a low or near low state , and therfore it believes the estop is still in the normal condition and not trigger

if you have additional opto's in the estop wiring it may need inverting to get the correct responce

but yes your looking for a 0v ( or near ) on your estop under normal use and then on triggering the estop the pin voltage should rise to 4.5v on a 5v system
are you using any of the mesa addon breakout boards by any chance ?

the following should get your estop working

net estop-out <= iocontrol.0.user-enable-out
net estop-ext => iocontrol.0.emc-enable-in
net enable => motion.motion-enabled

net estop-ext <=hm2_xxx.0.gpio.xxx.in ( edit for your pin )

cncbasher wrote:
I don't have it connected - this issue has stopped me in my tracks ...

I'm just building as I go along slowly so I can understand it all before proceeding - otherwise I fear I'll mess something up which will affect more and more and I have to start again.

So, the plan was just to have a little loop coming out of the Mesa card then straight back in with a NC switch in the middle - I thought 3.3v would do for now ... The output would feed the estop input thereby letting EMC know the loop was good or not. On top of that if the e-stop within Axis were hit (F1 or whatever) the physical system would know as even though the external switch (a traditional latching e-stop switch) hadn't opened it wouldn't be getting any voltage from EMC either (a relay for instance could be tapped off the loop)... So like I thought, the internal and external parts of the machine would be both capable of a proper estop and in turn both sides would also be made aware of the others estop 'command'...

So, yeh - just two wires at the moment that I want to be estopped when they are apart, and not estopped when they are together ... I just want to make sure that by inverting the logic than I dont stuff up some other part of EMC in terms of safety logic.

Is this something to do with floating pins (pull-up and so on?) - that stuff I am only half understanding so far...

Not sure what you mean by "you're looking for a 0v ( or near ) on your estop under normal use and then on triggering the estop the pin voltage should rise to 4.5v on a 5v system " - isn't that the opposite of what you've agreed with me earlier on ?

thanks for the response - I really want to get this right, even if it takes months - I'm getting there slowly

ok no problem , lets take it one step at a time

you should have one side of the estop and your limit switches connected to gnd (or 0v ) of the interface card via the ribbon cable , and the other connected to the input pin , when the the estop is activated it should open the connection
this will effectivly give you a 0v or near 0V in normal operation , at the input pin of the interface card , then on operation of the estop and opening of the estop switch this should cause the voltage on the input pin to rise to somewhere near 3v or 5v depending on your
installation as you do not say if your connecting directly to the card or via any interface such as the 7i42 etc , or opto couplers .


the correct way is to have the estop switch (s) in series all hardwired to release mains power via the contactor , use a seperate spare contact pair on the contactor relay to connect with emc , or a relay in series to the estop switches
never use any kind of software to operate in a safety enviroment , use it purely as an input for informational use and secondary to it's main purpose to inform emc .

by the time you have operated the mouse or hit f2 etc , the damage has already happend , and probably someones limb !