Have a compressor set up which takes 30s to build pressure on first power on. Using m8 to turn on. And off a demand valve and if I get m8 I ensure compressor is on. (small logo plc runs compressor).
So question is if on change of layer can I get a pause after the m8 comes on (for the first time} so compressor can build pressure, once pressure is up compressor will remain, on for 20mins so not an issue through rest of layer… Dont want a a pause at every time m8 goes high only first time.
I assume a macro should be able to do this or a bit of gcode… Bit like this
If air assist=on then m8 wait 30s start cut Else Start engrave End if
G4 P30
The LinuxCNC spec for G4, which is where GRBL started, says the units are seconds. Some forks use milliseconds, so if it doesn’t seem to pause, try multiplying by 1000:
G4 P30000