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Re:'It Was the First Time I Cried in the Operating Room' by jacquesm on Saturday January 27, 2018 @03:39AM (#16245391)
That's the perfect solution, and actually quite close to what I ended up doing. But you are still going to have to (1) detect the fact that there is an e-stop in progress, (2) restore the machinery to stable state afterwards and (3) lift the e-stop condition at some point.

And all of those will have a software component.

I've written a bit more about how it worked in another comment.

The big thing to keep in mind here is that an ST is a very limited machine when it comes to IO and that just about every port was already occupied so I somehow had to make this work safely without having additional ports for e-stop i/o in the budget.

If I had to do it again in the present I would never have consented to using such an I/O hamstrung platform to begin with and I would use an FPGA to do all the control logic.

Re:'It Was the First Time I Cried in the Operating Room' by taneq on Sunday January 28, 2018 @07:37AM (#16251026)
Bit of a late response, but I've read the other comments plus your "startup from hell" blog post - man, what a ride! Thanks for telling the tale!