Bookmark and Share 01 October 2003  Large-scale offshore
platform bus  Scrolling across InTech magazine's desk recently
came an exchange on wiring an offshore platform in Asia. The
questions come from Malaysia and are in italics. The answers
come from ISA member, fieldbus expert, and author Jonas Berge.
Berge operates from Singapore.  On the subject of offshore
environments and Exi/Exd instruments, I need counsel on the
large-scale use of Foundation fieldbus H1 (FFH1) for, say, all
400 transmitters and valve controllers wired to a conventional
distributed control system (DCS) on a 12,000-ton topsides
offshore platform.  Specific considerations are these:  1. The
platform is compact, so cost and weight savings for FFH1 are not
substantial compared with the use of remote I/O modules.  The
reduction is not just wiring and the associated cable trays and
ladders. Also consider that because no I/O modules and
marshalling are required and fewer controller central processing
units (CPUs) are required, you eliminate a