Mesa 7i96 and E-Stop

If the estop has a N/C you can feed from your stepper drive power supply to the estop then on to the stepper drives.

When you select the estop input it makes the changes to the configuration needed to coordinate the estop input with the software estop. IIRC that input needs to be a N/C switch as well.

JT

It's debatable if there is much point killing the power to steppers with the E-stop. They won't turn without step signals. In fact they will stop faster if powered up.

Also, disconnecting the DC side of the power is never a good idea, especially with inductive loads such as motors.
That usually ends up in smoke from the drives.

Yes.

Actually IIRC you need to use the N/C side for the input.

JT

Thank you JT,
It is better to use the NC side of things as it will not allow the machine to move if any wiring is interrupted.

kbec wrote:

So are you guys saying just to leave the normally closed side unconnected?, and just use the signal to do everything? 

Yes, but only in the case of stepper-motor based machines. 

If the PC locks up with a stepper system it will stop making steps. If it locks with a servo system it could leave the motors running at full speed. 

So, in the former case you can trust the PC to be alive if the motors are turning. 

You probably want to kill the spindle motor power in hardware, though. 

On my lathe the approach I took was to wire the main contactor power through the E-stop NC connector. Then I have an input to the controller that monitors the contactor coil voltage. So hard-estop triggers soft e-stop. But this is a fairly powerful servo system.