Hello satiowadahc,
I’m an applications engineer for Teknic and I came across your post. I’m sorry that you’re experiencing undesirable machine movement during a controller shutdown while the servo drive is still enabled. You've been working with my colleague here (and it sounds like you've also been implementing some other protective measures on the machine) - it's possible you've already fixed the issue, but I thought it might be helpful to post some additional relevant information in case anyone else experiences something similar and sees your post.
If a controller sends a static 5V signal, the drive would not respond (there isn’t any way for the drive to interpret a single high state as a command for motion). The Eclipse drives will only respond to step pulses (specifically, the falling edge of the change in state from a step pulse).
Digital devices rely on a voltage threshold to define high versus low signals. As a controller powers down, its output may decay and fluctuate around this threshold, creating multiple false transitions that the drive interprets as steps. The oscilloscope shots that you sent over to Teknic suggest that this is likely what's happening to the signal on the step line (as your controller powers down).
For safety, we recommend shutting down by first removing power (or disabling) the motion-generating device, then powering down the controller. Powering down the controller first introduces a fair amount of uncertainty because shutdown behavior varies across different controller manufacturers and configurations.
If you find that there is also noise on the signal, there are step input filters that can be programmed into your Eclipse Servo Drive to help with noise filtering, if you haven’t already configured that (there is more information on this in the Eclipse User Manual – pages 19-20).
I’d also recommend (if you haven’t already done so) grounding the Step and Direction lines according to the manufacturer's documentation. There are also instructions in the Eclipse User Manual that explain how to properly ground the signals to Eclipse.
I hope that this information is helpful. If you have any questions, please feel free to give Teknic a call (or contact the engineer that you’ve already been working with).
Best,
Andy O. – Teknic Servo Systems Engineer
