Installation guide

Introducing the Modbus Plus Network

890 USE 100 00

1.8 Designing for Process Speed

Figure 12 is an example of a hierarchical approach using Bridge Plus

devices. The application uses a relatively large count of nodes, but no

network contains more than six nodes.

Token access and message handling can be rapid within the networks

that are used for the control of timecritical processes. For example,

the node count on a given network can be reduced to the minimum that

is required for that portion of the application. Node counts on other

less-critical networks can be increased.

Message transactions across the bridges are slower than in single

networks, because the rotation times of the multiple networks are a

factor in receiving data responses from destinations. Because of this,

internetwork traffic should be dedicated to transactions that are less

critical for timing, such as for data collection and program

downloading.

BP = BRIDGE PLUS

BPBP

P230P230

BPBP

UI = USER INTERFACE

HOST

UI UI

UI UIUI UI

CPU

BPBP

CPU CPU CPU CPU CPU

CPU CPU CPU CPU CPU CPU

Figure 12 Hierarchical Configuration for Improved Throughput