Best posts made by Paulh

since it has just affected me I would make a warning that if the SSD relay fails and short circuits then the heated bed supply is switched on 100% and not controllable by the Duet. Yesterday my SSD failed and I found the 300mm diameter hotbed heated by my 240v supply to "240 degrees" (maybe it was more than that depending on the thermistor accuracy ). The Duet recognised it as a heating error (temp on the PanelDue was in purple) and no voltage was present on the SSD input. A new SSD fixed the problem, but I am going to put a further safety switch off system into place. Am researching this so looking at either a separate independent system apart from the Duet that will cutoff the 240v supply over a certain temperature, a relay controlled by the Duet to switch the heatbed 240v off when the Duet senses the heatbed error, a thermal fuse on the 240v line next to the heatbed that blows on high temperatures…...
Not sure how to switch the relay from the Duet which would be fairly simple. ..?via the 5v PSU control.