Status LEDs
LED locations
The board has three groups of status LEDs:
Power and ENA on the bottom-left;
TX/RX for RS-489 connnection 1 (UART0/1)
TX/RX for RS-489 connnection 5 (UART5)
Power, ENA and ESTOP
The power indicator is on when power is supplied to the HUB75HAT (either by the RPi or the 5A-75B). When this LED is on, DO NOT unplug the GPIO connector, as this may lead to irreversible damage to the RPi and/or 5A-75B.
The ENA indicator is on when the board got the _enable_ command from LinuxCNC. When this LED is on, signals from the 5A-75B will flow to the three I/O connectors. It is strongly recommended not to change connections from the I/O, as this may result in damage or unexpected movement of the machine.
Warning
In version 1.0 the ENA-LED is not working.
TX/RX status LEDs
Both RS-485 connectors have two LEDs indicating communication to and from the port.