Kinetix 300 enabling on startup

I am controlling a Kinetix 300 drive with a Micrologix 1100 using msg instructions. So far all is well. I am trying to put in as many bug fixes as I can before I ship the machine out.

I am using a PLC output for my hard-wired drive enable (29-26). When I cycle the PLC power and that hard-wired enable opens and then closes again I see the drive try to enable for a spilt second and the un-enable again. That it okay because I do not have any other signals going t the drive so the motor does not turn. It does cause a problem if my STO switch is open at the time. The STO on the drive is wired through a door safety switch. If that switch happens to be open when the PL power is cycled and the drive tries to enable the drive will go into a fault E39. Not the end of the world. I can clear it with a fault reset.

What troubles me is what could be causing it. It must be something that I have set in the drive setup because it does it even if I open and close the hard-wired enable without the PLC.

Anyone have any ideas? Is there something in the drive that does a split second diagnostic to see of the drive can enable properly? I hate little glitches like this that do not hurt but are just a pain...

Thanks in advance.

lurby said:

When I cycle the PLC power and that hard-wired enable opens and then closes again I see the drive try to enable for a spilt second and the un-enable again.

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That should not happen; generally speaking, no PLC Output should turn Off/On upon a power cycle; there should be more than one condition for any Output to be energized.

lurby said:

What troubles me is what could be causing it.

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It is a combination of my previous observation and the chosen control method- Explicit Messaging on a ML1100; yes, the manufacturer has documentation examples, however, personally, I would never use a servo-drive within a MicroLogix controlled system, Ethernet networked or not; the 'explicit' nature of the implemented control communications is barely implemented functionality and nothing else; obviously accuracy and safety were secondary considerations to cost...