Re: [CAD_CAM_EDM_DRO] Re: Safety -- servo vs. stepper

Leslie M. Watts wrote:

>Jon,
>
>Great!
>
>I didn't think emc wrote to the watchdog timer. A quick search of the code
>shows that it does. I'll have to do the jumpers and get that going.
>
>

You don't really need a special write to a watchdog, if you can
just monitor the writes to the DACs.

>I thought about the encoder failure mode...I think the estop on following
>error would happen awfully quickly at least on my system. It doesn't take
>long
>to go 0.1 inch at the speeds my machine would runaway at...
>
>

But, if the encoder fails, it is NOT SEEING the actual motion, it is seeing
NO MOVEMENT! That's the rub. The following error will only occur
after the computer has commanded a move equal to the following error
limit. If the commanded move just happened to be slow, then it would
take longer to accumulate that much error. Do you really have the following
error set at 0.1"?

Jon