Use EXT terminal block for laser duration recording ?

[PBrunot]

It could be useful in the future to record the actual time a machine is running (e.g. laser ON...) vs. time it is in used.
Laser machines in the lab have an output for laser running which could be connected to it.

Not sure if this is really useful for maintenance

Maybe the board should include a resistor divider to handle 5V signals on the EXT with high values R.