Control and safetyAn electrical cabinet, not a bare board
A Teensy 4.1 on a T41U5XBB breakout runs grblHAL, with separate inputs for every limit switch, the tool setter, the E-stop and the drive alarms. Normally-closed inductive switches fail safe; a tool setter measures tool length. In the steel cabinet, the E-stop opens the contactor that feeds the drives and the VFD, and a start button is needed after every power loss.
- Two-channel E-stop: contactor coil and controller input
- No automatic restart after a power cut
- Separate 48 V drive and 24 V control supplies