Make switching station only react to nodes from below

est31

2015-02-02 9444eff7f7853b0e4385adbd117cd6bace8dcb8f

 technic/register.lua

@@ -3,6 +3,7 @@

technic.receiver = "RE"
technic.producer = "PR"
technic.producer_receiver = "PR_RE"
technic.battery  = "BA"

technic.machines    = {}