I would like to trigger a relay to disconnect the spindle from mains power when the e-stop is depressed. This would be a much safer option and from some experience setting up a small mill with a MASSO controller is the preferred standard.
When e-stop is depressed, power to the spindle should be disabled both in software and “mechanically” from mains power. On spindles/VFD that support it, e-stop signals can apply breaking to stop the the spindle faster and lock out the spindle. I don’t know that the redline spindles / VFD have that capability.
Great idea. Currently, OUTPUT3 on the RTCNC controller is not dedicated to any gcode function. We can add functionality to make this output active when an e-stop is detected.
It should be noted that this will be a software connection from the RTCNC controller viewpoint. The actual e-stop hardware (switch) is external to the RTCNC controller. For optimal safety you would have to electrically route the power for the spindle through a switch block on the e-stop.
It may make more sense, as you mention, to control the relay mechanically through the e-stop button, rather than use up the last remaining free output. I didn’t think of it from that perspective, and I’ve peeked inside Redlines HMI and can see that it’s probably quite possible to do so.
Hardware modification as opposed to software, but hey who doesn’t have a step bit, a soldering iron some odd ball wire sizes lying around and a willingness to void their warranty!
In all seriousness I believe you’re correct that my use case is better addressed mechanically as opposed to through software. If you have a failure on the electronics side of things, and the output is not triggered appropriately, you won’t adequately disarm the spindle.