External E-Stop

BigJohnT wrote:

This method uses the ESTOP_LATCH component to connect up an external physical E-Stop to LinuxCNC.

net remote-estop estop-latch.0.fault-in <=  hm2_5i20.0.gpio.025.in_not

Well, if you are going to post hardware-specific code, I have to match that with the
code that I use with my hardware.

This links up a hardware Estop sense circuit and estop latch
with a software one in LinuxCNC. Anthing that breaks the
Estop sense loop in the hardware, or a software command
to go to E-stop will cause both hard and soft E-stop latches
to go to E-stop. Only when the hardware Estop chain is
closed and the software command is given to come out of E-stop
will it do so. The hardware also has a watchdog timer to cause
an E-stop if LinuxCNC stops controlling it.
The timing of these functions is critical, as handled
by the order of addf's in the ppmc_load.hal file.
addf motion-command-handler servo-thread
addf and2.0 servo-thread
addf estop-latch.0 servo-thread
addf motion-controller servo-thread

Since there is a delay of one servo cycle between sending a command to
the hardware and reading back the status, these operations have to be
done in the right order.

Jon

BigJohnT wrote:

jmelson wrote:

Well, if you are going to post hardware-specific code

That was not my intention I just quickly copied and pasted the example I had at hand.

John

Just a little ribbing, I should have thrown in one of those
emoticons!

Jon

I am trying to get my estop to work - and saw your example, I am going to do some experimenting but wondered if the line

net remote-estop estop-latch.0.fault-in <= parport.0.pin-in10-not

should be

net remote-estop estop-latch.0.fault-in <= parport.0.pin-10-in-not

I also wondered what the line 'addf estop-latch.0 servo-thread' does - I don't have servos, I have stepper motors??

Regards

Chris

# estop
loadrt estop_latch
addf estop-latch.0 servo-thread
net estop-loopout iocontrol.0.emc-enable-in <= estop-latch.0.ok-out
net estop-loopin iocontrol.0.user-enable-out => estop-latch.0.ok-in
net estop-reset iocontrol.0.user-request-enable => estop-latch.0.reset
net remote-estop estop-latch.0.fault-in <= parport.0.pin-in10-not

Thanks for posting this. My E-stop circuit is now improved.
I'd like to add my limits to the estop circuit through software if necessary. As physically wired, I can't run the limits in series with the estop. What is your opinion on this? This would protect the machine only from a drive failure. I'm using DMM servo drives in step mode and I don't know how they would react if an encoder wiring would fail down the road. Runaway? Or is it safe enough to rely on a drive enable signal to disable the drive? Linking the limit signal to disable the drives?

I know this is an old thread but it helped me get my estop working.

Here is a working config from my system running Master branch 2.8 and a Mesa 7i96 board. My estop button is N/C and is a 24 volt input to GPIO 010 on the Mesa board. Just change the last line for your particular board and GPIO pin.

# ---estop signals---
# create a signal for the estop loopback
#config from BigJohn#
loadrt estop_latch
addf estop-latch.0 servo-thread
net estop-loopout iocontrol.0.emc-enable-in <= estop-latch.0.ok-out
net estop-loopin iocontrol.0.user-enable-out => estop-latch.0.ok-in
net estop-reset iocontrol.0.user-request-enable => estop-latch.0.reset
net remote-estop estop-latch.0.fault-in <= hm2_[HOSTMOT2](BOARD).0.gpio.010.in_not