diff --git a/palm_scanner.lua b/palm_scanner.lua
index 5f07ea7..9fb8a53 100644
--- a/palm_scanner.lua
+++ b/palm_scanner.lua
@@ -9,53 +9,38 @@
 
 local has_mesecons = minetest.get_modpath("mesecons")
 
--- after_place_node
--- placer is a player object
-local function set_scanner_owner(pos, placer, itemstack, pointed_thing)
-	local meta = minetest.get_meta(pos)
-	meta:set_string("owner", placer:get_player_name())
-end
 
-local function toggle_palm_scanner(pos, node, player, itemstack, pointed_thing)
-	-- Some calling function don't send node param, but everybody sends a pos, so :
-	if not node then
-		node = minetest.get_node(pos)
-	end
+function activate_palm_scanner(pos, node, player)
+	local name = player and player:get_player_name()
+	name = name or ""
 
-	if node.name == "scifi_nodes:palm_scanner_off" then
-		local meta = minetest.get_meta(pos)
-		meta:set_string("clicker", player:get_player_name()) -- need to keep it somewhere
-		minetest.swap_node(pos, {name = "scifi_nodes:palm_scanner_checking", param2 = node.param2})
-		minetest.sound_play("scifi_nodes_palm_scanner", {max_hear_distance = 8, pos = pos, gain = 1.0})
-		minetest.chat_send_player(player:get_player_name(), "Checking : please wait.")
-		minetest.get_node_timer(pos):start(2)
-	elseif node.name == "scifi_nodes:palm_scanner_checking" then
-		minetest.swap_node(pos,{name = "scifi_nodes:palm_scanner_on", param2 = node.param2})
-		mesecon.receptor_on(pos, scifi_nodes.get_switch_rules(node.param2))
-		minetest.get_node_timer(pos):start(2)
-	elseif node.name == "scifi_nodes:palm_scanner_on" then
-		minetest.sound_play("scifi_nodes_switch", {max_hear_distance = 8, pos = pos, gain = 1.0})
-		minetest.swap_node(pos, {name = "scifi_nodes:palm_scanner_off", param2 = node.param2})
-		mesecon.receptor_off (pos, scifi_nodes.get_switch_rules(node.param2))
-	end
-end
+	node.name = "scifi_nodes:palm_scanner_checking"
+	minetest.swap_node(pos, node)
 
--- palm_scanner_checking.on_timer
-local function check_owner(pos, elapsed)
-	local meta = minetest.get_meta(pos)
-	local owner = meta:get_string("owner")
-	local clicker = meta:get_string("clicker")
-	local node = minetest.get_node(pos)
-	if clicker == owner then
-		minetest.sound_play("scifi_nodes_scanner_granted", {max_hear_distance = 8, pos = pos, gain = 1.0})
-		minetest.chat_send_player(clicker, "Access granted !")
-		toggle_palm_scanner(pos)
-	else
-		minetest.chat_send_player(clicker, "Access refused !")
-		minetest.sound_play("scifi_nodes_scanner_refused", {max_hear_distance = 8, pos = pos, gain = 1.0})
-		minetest.swap_node(pos, {name = "scifi_nodes:palm_scanner_off", param2 = node.param2})
-		mesecon.receptor_off(pos, scifi_nodes.get_switch_rules(node.param2))
-	end
+	minetest.sound_play("scifi_nodes_palm_scanner", {max_hear_distance = 8, pos = pos, gain = 1.0})
+	minetest.chat_send_player(name, "Checking : please wait.")
+
+	-- check protection
+	minetest.after(2, function()
+		if minetest.is_protected(pos, name or "") then
+			-- clicker has no access to area
+			minetest.chat_send_player(name, "Access denied !")
+			minetest.sound_play("scifi_nodes_scanner_refused", {max_hear_distance = 8, pos = pos, gain = 1.0})
+
+		else
+			-- clicker can build here
+			minetest.chat_send_player(name, "Access granted !")
+			mesecon.receptor_on(pos, scifi_nodes.get_switch_rules(node.param2))
+
+		end
+
+		-- reset state
+		minetest.after(1, function()
+			node.name = "scifi_nodes:palm_scanner_off"
+			minetest.swap_node(pos, node)
+			mesecon.receptor_off(pos, scifi_nodes.get_switch_rules(node.param2))
+		end)
+	end)
 end
 
 minetest.register_node("scifi_nodes:palm_scanner_off", {
@@ -76,8 +61,7 @@ minetest.register_node("scifi_nodes:palm_scanner_off", {
 			state = (has_mesecons and mesecon.state.off)
 		}
 	},
-	after_place_node = set_scanner_owner,
-	on_rightclick = (has_mesecons and toggle_palm_scanner),
+	on_rightclick = (has_mesecons and activate_palm_scanner),
 	sounds = default.node_sound_glass_defaults(),
 })
 
@@ -96,8 +80,7 @@ minetest.register_node("scifi_nodes:palm_scanner_checking", {
 	paramtype2 = "wallmounted",
 	groups = {cracky=1, oddly_breakable_by_hand=1, not_in_creative_inventory=1, mesecon_needs_receiver = 1},
 	drop = "scifi_nodes:palm_scanner_off",
-	sounds = default.node_sound_glass_defaults(),
-	on_timer = check_owner,
+	sounds = default.node_sound_glass_defaults()
 })
 
 minetest.register_node("scifi_nodes:palm_scanner_on", {
@@ -120,7 +103,6 @@ minetest.register_node("scifi_nodes:palm_scanner_on", {
 			state = (has_mesecons and mesecon.state.on)
 		}
 	},
-	on_timer = (has_mesecons and toggle_palm_scanner),
 	sounds = default.node_sound_glass_defaults(),
 })