Author Topic: Closed loop stepper fault input  (Read 381 times)

calisto

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Closed loop stepper fault input
« on: September 09, 2021, 09:55:07 AM »
I am retrofitting my Bridgeport mill. I have chosen Mach 4, PMDX 424 and StepperOnline 12N-m closed loop stepper motors for the conversion. I am having trouble with my x axis faulting out and I would like for the system to shut down if one of my drives faults out. I currently do no have the ALM+ and ALM- (from the drives) wired into my SmartBOB because I am uncertain how to go about doing it. Can I simply wire these in series with my E-Stop (pin 27 and 28). Please advise

12strings

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Re: Closed loop stepper fault input
« Reply #1 on: September 13, 2021, 12:04:09 AM »
You should be able to connect all of the ALM- wires together and connect them to the PMDX-424's "COM" terminal on the EStop connector (J14).  Then tie all the ALM+ wires together and connect them to the PMDX-424's FAULT terminal on J14.  The PMDX-424 provides a pull-up on the FAULT terminal.  As best I can tell from the StepperOnline Y series closed loop stepper driver manual, a fault condition will turn on the driver's opto-coupler, thus shorting ALM+ to ALM-, which will then connect the PMDX-424's FAULT input to COM, which will disable the PMDX-424 same as an EStop.  And the FAULT going active gets reported to Mach4 same as an EStop.

calisto

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Re: Closed loop stepper fault input
« Reply #2 on: September 14, 2021, 02:46:45 PM »
Thank you. I will try that out