An MTL8000 node uses a Bus Interface Module (BIM) to communicate with the host controller via a local area network (LAN). Different BIMs can be chosen to operate with a range of popular fieldbus protocols. The BIM mounts on a carrier and receives all of its communication and power links from it. The BIM uses the RS485 communications standard. Other alternatives are RS422, by changing switches (where available) on the carrier, or RS232 by fitting an in-line converter. Switch options sometimes offer alternative methods for terminating the LAN. Some BIMs also have a second LAN connection to maintain communications in the event of damage occurring to the main communications link.