Bandwidth Monitoring

Introduction

offers two types of services:

real time: High-performance and predictable behavior are expected from services such as:
- periodic services: I/O Scanner and Global Data
- non-periodic services: Messaging on port 502 (Modbus)
other: for Web and network management

After you configure the , it is possible to estimate the load percentage of the module for this service.

The Bandwidth Monitoring function carries out this estimate during configuration.

The actual distribution of service loads is shown on the module’s diagnostics screen and on the diagnostics services bandwidth monitoring Web page.

Operation

In order to estimate this load, Control Expert asks you to supply two pieces of information during configuration:

an estimate of the number of messaging transactions per second
an estimate of the number of Global Data subscriptions received per second

Using this information, the software is able to display the load percentage of the module for:

NOTE: During the configuration phase, these pieces of information are only estimates. The actual distribution is displayed in online mode.

Modbus

Modbus is an application layer messaging protocol. Modbus provides client and server communications between devices connected on different types of buses or networks. Modbus offers many services specified by function codes. There are two types of Modbus transmission, based on information in the physical layer:

MB/serial: the Modbus type that transmits data over serial RS-232 and RS-422/485
MB/TCP: the Modbus type that transmits data over Ethernet

Unity Pro

Unity Pro is the programming software for all Unity PLCs. It includes 5 IEC languages that comply with IEC 61131-3. Depending on requirements, the application may use a mixture of different languages.

NOTE: Unity Pro is the former name of Control Expert for version 13.1 or earlier.