Runlevel 6 on Unix/Linux systems is a reboot. Runlevel 0 is a shutdown. Using either the init or telinit scripts as superuser will get you to your desired runlevel. Running init 6 as root or superuser will reboot your system. Running init 0 as root or superuser will shut your system down. There are other runlevels that do various things, such as runlevel 1 which puts the machine in singleuser mode.
Mark On Wed, Feb 16, 2022 at 12:13 PM Chris Albertson <albertson.ch...@gmail.com> wrote: > This is the problem with an instant acting switch. The pi gets one if the > GPIO pins low and the replay opens, shutting down power but then the power > is removed before the OS shuts down potentially corrupting storage. > > I think the only solution is the solution that every modern electronic > device uses. Turing on your using a remote control is the same problem. > The TV has to issue a command to the relay that controls power, put how to > do that if the TV is off? > > Solution, there is a second power control processor that controls the > power. The "processor" can be a dumb delay timer but today > microcontrollers are cheaper than timers and allow you to have functions > like sequencing at no extra cost but software. Even cheaper are power > management chips but those are designed for use inside the power supply. > > > You will need to implement somekind of a delay device that is triggered by > the Pi as it goes into Run Level 6 (I think 6 is "shutdown"?) The same > controller can monitor the power button and when moved from off to on start > the Pi, wait for it to boot then turn on the CNC motor power. The Pi > wouldtalk to the controller with a GPIO pins or use some serial interface > like I2C. I woulduse whatever serial interface is easy to program on the > microcontroller. > > This power controller would tie into e-stop also. The e-stop that comes > from the user interface would send a signal over that interface to drop > power to the motors. Yes the "real" is best but now you can make the > software one a little better. > > > > On Wed, Feb 16, 2022 at 6:17 AM Thaddeus Waldner <thadw...@gmail.com> > wrote: > > > > Just use a simple 10A relay with 5V coil > > > As a latch, you press a button to power up, ie power the coil, then the > > > same line gets dropped by the Pi to power off.. > > > > How does the pi drop the 5v line after shutting down? > > > > _______________________________________________ > > Emc-users mailing list > > Emc-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
