Hard wired input to gcode

Hello,

I have been working on retrofitting an old Bulleri 3-axis CNC router with linuxcnc. Now this router is equipped with a large vacuum table, powered by two independently controlled vacuum pumps. This allows for one side to be loaded by the machinist, while the other side is being machined.

My first attempt at using both tables was to have two seperate gcode files, each referring to different offsets (G54, G55.....) but this is quite tedious to keep loading files in between program runs.

I am on my second attempt where I am thinking if it is possible to have an input into the 7i77 from the vacuum sensors (each pump is equipped with a feedback vacuum sensor). Is it possible, through HAL / gladeVCP configuration, to have linuxcnc automatically select G54/G55 accordingly (in between program runs of course) depending on which of two inputs is currently HIGH?

PS. I am having the shop cleaned up so I should be able to post some photos of the machine shortly

Thanks!

Yes it is possible

Look at www.linuxcnc.org/docs/devel/html/gui/halui.html

and halui.mdi for example, you could trigger a mdi command to pass the co-ordinate system change

regards