Den ons 9 dec. 2020 kl 02:27 skrev Gregg Eshelman via Emc-users < emc-users@lists.sourceforge.net>:
> The way to wire an emergency stop circuit with 2 or more things that can > trigger it, is to have it a normally closed circuit and every stop switch, > mechanical or electronic, in series. > That way when anything triggers a stop it opens the circuit, the > controller senses that and stops sending motion commands, shuts off the > spindle(s), pump(s) etc. > What does this controller mean by "high" if "low" is grounded? If "high" > is open circuit then you should be able to connect every fault sensor and a > normally open E-Stop button in parallel. You'll also need to have the new > control hardware and software able to be set to use a closed circuit > instead of open circuit as the E-Stop condition. > If "high" is something other than open circuit then things get more > complicated. One may curse the engineer(s) who thought that making things > more complex than open or closed was a neat idea. ;) > A NC E-Stop circuit is quite fail safe because if a switch fails or a wire > breaks, the circuit goes open and the machine stops. If a wire breaks in a > NO circuit then the E-Stop button or sensor the broken wire goes to cannot > initiate a stop. > On Tuesday, December 8, 2020, 04:19:16 PM MST, Sven Wesley < > svenne.d...@gmail.com> wrote: > > Friends, > > > > I am in the process of refreshing a CNC that has been running in > "temporary > > state" the last 12 years, time to give it an overhaul. I've found the > magic > > little piece we all call 7i96. It will do magic. > But this isn't an E-stop circuit though, it's an error signal from the drive that can/should be reacted upon. It makes total sense to have an active low on such wire. If the drive dies completely the signal will disappear as well. Regards, Sven _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
