on_punch = function(pos, node, puncher, pointed_thing)
        if puncher:is_player() then
            print(puncher:get_player_name() .. " pounded the alarm at ")
            print(pos)
        end

        local setchan = minetest.get_meta(pos):get_string("channel")

        rules = {{x=0,  y=0,  z=-1}, -- taken from digilines.default.rules thing
            {x=1,  y=0,  z=0},
            {x=-1, y=0,  z=0},
            {x=0,  y=0,  z=1},
            {x=1,  y=1,  z=0},
            {x=1,  y=-1, z=0},
            {x=-1, y=1,  z=0},
            {x=-1, y=-1, z=0},
            {x=0,  y=1,  z=1},
            {x=0,  y=-1, z=1},
            {x=0,  y=1,  z=-1},
            {x=0,  y=-1, z=-1}}

        digilines:receptor_send(pos, rules, setchan, "fire")

        -- TODO: store the name of the puncher in somewhere permanent
    end,

-- Breaks and gives:

AsyncErr: Lua: Runtime error from mod 'firesafety' in callback node_on_punch(): /tmp/.mount_MineteFpGKBh/usr/bin/../builtin/game/misc_s.lua:13: attempt to perform arithmetic on field 'z' (a nil value)
stack traceback:
    /tmp/.mount_MineteFpGKBh/usr/bin/../builtin/game/misc_s.lua:13: in function 'hash_node_position'
    /home/independent/.minetest/mods/digilines/init.lua:50: in function 'receptor_send'
    ...dent/.minetest/mods/mymods/fire_safety_new/fireboxes.lua:57: in function <...dent/.minetest/mods/mymods/fire_safety_new/fireboxes.lua:36>