Installation guide

Estimating Network Performance

890 USE 100 00

3.4 Factors That Affect Performance

3.4.1 Handling Multiple Operations

The time that is required for a node to respond to a request for data is

affected by the count of nodes on the network, by the number of active

transactions in each node, and by each node’s instruction handling

capability (scan time). The way in which you program your application

also will affect the response time.

MODBUS PLUS NETWORK

COMPUTER

P230

PROGRAMMING

CONTROLLER

PANEL

CONTROLLERCONTROLLER COMPUTER

P230

PROGRAMMING

PANEL

NODE

A B

Figure 28 Handling Multiple Operations

Consider the Multiple Operations example again (see Figure 28.) Data

transfers are in progress between controllers 2 and 4. Computer A is

operating as a user interface obtaining data from controllers 2 and 4.

These two operations can be considered to be the ones that are most

critical for timing, because they are handling application data in real

time. These operations are also interactive, because the application

uses Computer A as an interface accessing data in the controllers 2 and

4. Data paths and application program instructions must be provided

in these controllers for servicing the user interface, in addition to

servicing their mutual data requirements.