Servo/stepper alarms in general, specifically AXBB-E to Delta ASDA-B2 servos?
I'm trying to understand how to properly connect a CNCdrive AXBB-E controller to Delta ASDA-B2 servo drivers.
Background:
1. This machine (AlphaCNC AMN-6040-M) came pre-configured with an XHC MK4-V controller & Delta ASDA-B2 (750W) servos. The XHC controller has been problematic (mostly probing) which is why I'm replacing it with the AXBB-E.
2. E-stop never worked correctly on this machine using the XHC controller. When I tried to troubleshoot it, I ended up assuming the cause was that the 4th-axis (rotary) wasn't hooked up, putting the driver into AL0011 alarm condition, which triggered the e-stop condition. Since the controllers were wired to e-stop, I didn't trace it further. Using Mach3, I just double-reset past the issue and moved on.
3. Currently I have pulse and direction signaling working with the AXBB using the unbuffered digital outputs. So I can jog the servos.
Question (detailed):
My problem is, I've replicated the XHC e-stop wiring to the I1-/I1+ buffered inputs and it doesn't work as expected.
I expected the alarming servo to pull the signal low, triggering e-stop. I planned on just unplugging CN1 on that driver to bypass the issue for now. But that didn't happen.
If I disconnect the servos from the estop circuit, leaving just the estop button, the estop button works as expected.
Strangely (at least to me), tracing the connections, all the servo drivers had GND(CN1 pin-19) tied to +0V on the 24V-out circuit & V_REF(CN1 pin-20) to Estop on the XHC controller. The machine's e-stop button was also tied (in parallel) to this as well.
Was the original intention for the e-stop button to pull V_REF low, halting the servos? If so it seems bad to put +24V on a pin that's only supposed to see +10V maximum. And does this even make sense? estop should stop the step signals, doing the same thing.
Is there a way for the AXBB to detect the servos fault signal (ALRM digital output wired to I1/estop or otherwise)?
Question summary: What is the recommended way to wire servo alarms, estop, etc to the AXBB controller?
Sorry if this post sounds confused, it's because I am. My goal is to:
1. e-stop should work
2. servo alarms should properly stop the machine
I'm kind of struggling here with my machine down, so any help would be desperately appreciated!
Re: Servo/stepper alarms in general, specifically AXBB-E to Delta ASDA-B2 servos?
Hi,
I'm currently wiring my Delta B2 series servo drives to my breakout board/ESS and Mach4 combination.
On page 3-30 of the ASD_B2 manual I'm following the diagram C5 within the the exception that I'm not using the 24V supply within the drive.
My breakout board has an independent 24V supply but shares a common earth, COM-. Thus the collector of the transistor will pull low when the alarm is active.
I have one alarm per servo. Any one alarm will pull low and that will in turn EStop the machine.
Note that I'm am relying on any one servo alarm to pull the EStop line low and the machine controller Estops.....so all servos stop. Note however that there is an Emergency
DI input, should you choose to program it, which would accomplish the same thing. I'm not sure that either method has a clear advantage.
One possibility that I might exploit at a later date is to have several alarms from each servo. Usually overheat, over voltage and over current are immediate Estop events
whereas 'following error' deserves to stop the machine but I would prefer <Feedhold> followed by <Stop> rather than EStop. In short some alarms are catastrophic an should
be handled differently to other conditions. I have quite a few spare digital inputs spare on my controller so that upgrade is a possibility. If you are struggling for inputs
then such a scheme will not work for you.
Because I use Mach4 I will edit the screen set to include a 'Fault LED' for each servo. Thus I will know which axis has faulted should the machine EStop. I will have one ServoReset
output from my controller that will reset all servo drives together.
Servo/stepper alarms in general, specifically AXBB-E to Delta ASDA-B2 servos?
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