I am running grbl mega with Ramps 1.6. A Mega2560 with a Ramps 1.6 board. I'm led to believe the pinouts are the same as Ramps 1.4. Using OpenBuilds Control the motors run fine but when I hit the limit switch it doesn't put the machine in an Alarm state as it should. I have hard limits enabled using NO switches. If I click the Troubleshooting tab the limit box responds when I activate the switch, so the signal is getting thru. So whats going on?