Profinet Network Arrangement; System And Dual Bus References - Emerson PACSystems RX3i Application Manual

Application Guide
GFK-2928C
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3.1

PROFINET Network Arrangement

A ring topology using MRP is the preferred arrangement. With this topology, a system may
use a combination of PROFINET System Redundancy (PNSR) devices and non-PNSR devices
(specifically Genius Communication Gateway modules).
Also, systems may incorporate managed network switches that support MRP. The approach
is particularly useful for large systems that are upgraded incrementally. In this case, Genius
dual busses (each consisting of four GCG modules – Primary A & B, Secondary A & B) may be
grouped into one of multiple subrings.
3.2

System and Dual Bus References

Figure 3: System and Dual Bus References
Each Genius device that has been configured to have discrete inputs must have one block of
references assigned to Bus A and a separate unique block of references assigned to Bus B.
The application logic is always solved using the references that are assigned to Bus A. There
is fixed offset that specifies the location of Bus B references relative to Bus A.
The references for analog inputs are configured in a similar fashion.
The offset for discrete inputs (DI_OFST) and the offset for analog inputs (AI_OFST), as shown
above, are recommended values. However, they may be configured independently for each
dual bus pair.
Application System Architecture
Optional – Connectors that provide Hand Held Monitor attachment points for each of
the Genius busses. (Emerson catalog number 44A736310-001-R001. Refer to Genius
Hand-Held Monitor User's Guide, GFK-0121, page 2-9 for further information).
Chapter 3
Oct 2019
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