New PLC; SCADA system with flow control

Hello everybody
we have new project with 2 CPU working in redundancy and requirement to arrange (AGA report 3) blocks based on orifice flow calculations based on defined constants for density and viscosity.

1. what is the best RA family can achieve redundancy basis and meet AGA report 3 requirements?

2. What is the modules can do the flow calculations in accordance with AGA 3 as described above?

Thanks in advance

ControlLogix and Prosoft flow computer.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

http://www.prosoft-technology.com/P...gix/Gas-Liquid-Flow-Computer-for-ControlLogix