The series 9494 bus rails are used as a backplane bus for the IS1+ remote I/O system. They include an I.S. power bus boasting high availability, a redundant I.S. data bus and address lines. The bus rails are available for 2 or 4 modules and can be combined for up to 18 slots. The BusRail extension cable can be used to place BusRail segments anywhere in the field enclosure.