AutoPASS is the Norwegian system for electronic payment of tolls. If you have a valid one AutoPASS agreement you will be able to pass through the toll plaza without stopping. The passage will be charged from the company where you got your chip.
You only get discount from the toll company at which you have signed the agreement. If you want more discount from other companies, you must sign an agreement with each company.
For more information see the website Autopass: www.autopass.no