DOCA0172EN-12

Modbus TCP/IP Server

Presentation

Modbus TCP/IP devices connected downstream the Panel Server can be accessed from an upstream SCADA system.

Availability

This function is available on Panel Server Entry , Universal , and Advanced .

Setting the Parameters

Modbus TCP/IP server function is set as follows:

  • With EcoStruxure Power Commission (EPC) software

  • On the EcoStruxure Panel Server webpages, at Settings > Modbus devices > Modbus configuration > Modbus TCP server .

Modbus TCP Server Settings

The following table describes the settings and where they are available.

Parameter Description EPC software Webpages

Message timeout (ms)

In Modbus network configuration, you can set the message timeout period for the Modbus TCP server.

Setting used to set the time-to-live of a Modbus request in the Panel Server . Any messages older than this setting will be dropped.

Values from 1,000 to 320,000 ms (default setting: 6,000 ms)

The value that you set for the Modbus TCP server must meet both following conditions:

  • Be equal to the message timeout that is defined on the upstream Modbus client (SCADA or another Panel Server ).

  • Be higher than the timeout defined in the Panel Server Modbus client setting (Modbus TCP/IP and Modbus-SL).

For recommended parameter settings, see details below.

In the Panel Server , the following settings are recommended for the message timeout: the value of message timeout for Modbus TCP server should be double the value of message timeout for Modbus client.

Message timeout for Modbus TCP server is called Upstream timeout and message timeout for Modbus client is called Downstream timeout as shown in the diagram.

x: Basic response time of the end device

s: Small amount of additional time (margin)

Upstream timeout: Message timeout setting for Modbus TCP server

Downstream timeout: Message timeout setting for Modbus client

How to configure the message timeout in a parent/child Panel Server architecture

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