axis emergency stop
19 Jan 2013 19:33 #28819
by no-bug
axis emergency stop was created by no-bug
hello
using axis 2.5.1
I noticed that the emergency stop signal remain in the high state when you close the Axis window. By cons, the enable signal goes from high to low and that seems correct.
What the reason for thisabout ESS?
would it not be better that he ES signal goes to the low state to cut the power when the Axis window is closed?
using axis 2.5.1
I noticed that the emergency stop signal remain in the high state when you close the Axis window. By cons, the enable signal goes from high to low and that seems correct.
What the reason for thisabout ESS?
would it not be better that he ES signal goes to the low state to cut the power when the Axis window is closed?
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19 Jan 2013 19:47 #28820
by cncbasher
Replied by cncbasher on topic axis emergency stop
E Stop is a normaly closed contact , rather than normaly open , this gives more security to the estop circuit in that any breaks in hardware wiring are also interpreted as an estop condition
where an open contact would not , hence why this signal stays in a high state .
Estop is more hardware than software orientated , within Linuxcnc it is not meant to control it's more to inform Axis of an estop condition ,
to control hardware use the Amplifier Enable to control drivers or switch on or off machines .
it is not recommended to rely on software for Emergency situations , or indeed switch on hardware without some manual intervention .
where an open contact would not , hence why this signal stays in a high state .
Estop is more hardware than software orientated , within Linuxcnc it is not meant to control it's more to inform Axis of an estop condition ,
to control hardware use the Amplifier Enable to control drivers or switch on or off machines .
it is not recommended to rely on software for Emergency situations , or indeed switch on hardware without some manual intervention .
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19 Jan 2013 20:10 - 19 Jan 2013 23:08 #28822
by no-bug
Replied by no-bug on topic axis emergency stop
I agree with that ES is hard. But I think that if the EMC2 ES out signal can disable power when the EMC2 Axis window closes (with a relay contact "and logical wired" in emergency stop chain ) , it whould be better. See add file.
Last edit: 19 Jan 2013 23:08 by no-bug.
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22 Jan 2013 22:31 #28969
by andypugh
Replied by andypugh on topic axis emergency stop
My system does. But this is more related to the amp-enable signals than the E-stop chain.I agree with that ES is hard. But I think that if the EMC2 ES out signal can disable power when the EMC2 Axis window closes
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22 Jan 2013 22:43 #28971
by cncbasher
Replied by cncbasher on topic axis emergency stop
as Andy has mentioned , better to use the Amplifier Enable for this , that way you still have control over Linuxcnc , where using the Estop would also require rehoming .. and is essentialy switching the machine off by mains and not via software .
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20 Feb 2013 17:45 #30357
by no-bug
Replied by no-bug on topic axis emergency stop
Hello
It seem that I have not been clear in my problem description.
I know that ES is harware controlled, but Axis can send ES signal to the hard ES chain ("AND" wired). The question is about when u end an EMC-Axis session by closing the windows (when u end your job for instance). I have plug a oscilloscope probe on the ES out pin of the parallel port and notice that the signal does not change and does not send ES to the ES hard chain.
I agree that enable-signal changes when u close de EMC-Axis windows, but I thing that it is not enough.
It seem that I have not been clear in my problem description.
I know that ES is harware controlled, but Axis can send ES signal to the hard ES chain ("AND" wired). The question is about when u end an EMC-Axis session by closing the windows (when u end your job for instance). I have plug a oscilloscope probe on the ES out pin of the parallel port and notice that the signal does not change and does not send ES to the ES hard chain.
I agree that enable-signal changes when u close de EMC-Axis windows, but I thing that it is not enough.
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20 Feb 2013 18:35 #30360
by Rick G
Replied by Rick G on topic axis emergency stop
As I understand it when you shut down EMC it longer controls the parallel port. So I always power down my machine before closing the window.
Are you saying that EMC should send the signal before shutting down?
Rick G
Are you saying that EMC should send the signal before shutting down?
Rick G
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20 Feb 2013 20:38 #30364
by BigJohnT
Once you turn off the software the state of the parallel port is unknown and is no longer being controlled. If you require a known state after power down you need to have a charge pump circuit.
John
Replied by BigJohnT on topic axis emergency stop
Hello
It seem that I have not been clear in my problem description.
I know that ES is harware controlled, but Axis can send ES signal to the hard ES chain ("AND" wired). The question is about when u end an EMC-Axis session by closing the windows (when u end your job for instance). I have plug a oscilloscope probe on the ES out pin of the parallel port and notice that the signal does not change and does not send ES to the ES hard chain.
I agree that enable-signal changes when u close de EMC-Axis windows, but I thing that it is not enough.
Once you turn off the software the state of the parallel port is unknown and is no longer being controlled. If you require a known state after power down you need to have a charge pump circuit.
John
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21 Feb 2013 01:11 - 21 Feb 2013 01:19 #30371
by no-bug
Replied by no-bug on topic axis emergency stop
Hello Rick
Yes, I think that if Axis sends ES signal via out pin port, it whould be a clean way to power-off the machine. And to reply to BigJohnT, once the ES send to the chain by Axis while it is shutting down, the state of the port does not matter anyway once the machine in ES state (I whould remind everyone that the problem is when closing only EMC-Axis application).
Yes, I think that if Axis sends ES signal via out pin port, it whould be a clean way to power-off the machine. And to reply to BigJohnT, once the ES send to the chain by Axis while it is shutting down, the state of the port does not matter anyway once the machine in ES state (I whould remind everyone that the problem is when closing only EMC-Axis application).
Last edit: 21 Feb 2013 01:19 by no-bug.
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21 Feb 2013 10:50 #30395
by skunkworks
Replied by skunkworks on topic axis emergency stop
Use a charge pump or watch dog circuit - that is one thing they are for. (when linuxcnc isn't in control - estop)
(there is or used to be a posthal file... That may or may not do what you want.)
linuxcnc.org/docs/2.5/html/config/ini_co...id_sub_hal_section_a
SHUTDOWN = shutdown.hal - Execute the file shutdown.hal when LinuxCNC is exiting. Depending on the hardware drivers used, this may make it possible to set outputs to defined values when LinuxCNC is exited normally. However, because there is no guarantee this file will be executed (for instance, in the case of a computer crash) it is not a replacement for a proper physical e-stop chain or other protections against software failure.
sam
(there is or used to be a posthal file... That may or may not do what you want.)
linuxcnc.org/docs/2.5/html/config/ini_co...id_sub_hal_section_a
SHUTDOWN = shutdown.hal - Execute the file shutdown.hal when LinuxCNC is exiting. Depending on the hardware drivers used, this may make it possible to set outputs to defined values when LinuxCNC is exited normally. However, because there is no guarantee this file will be executed (for instance, in the case of a computer crash) it is not a replacement for a proper physical e-stop chain or other protections against software failure.
sam
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