The following sections provide some guidelines for using fieldbus function blocks in DeltaV control applications. Remember that all fieldbus function blocks in a control module must execute on the same fieldbus segment. The H1 card can run a total of 96 function blocks: 32 (maximum) H1 card fieldbus blocks and 64 (maximum) DeltaV non-H1 card fieldbus blocks. The 96 function blocks can execute on either port. A maximum of 16 devices can run on a segment.