Template:Networking rut manual modbus

Summary

Modbus is a serial communications protocol. Simple and robust, it has since become a de facto standard communication protocol and is now a commonly available means of connecting industrial electronic devices. This chapter is an overview of the Modbus TCP functionality.

Modbus TCP

Modbus TCP provides users with the possibility to set or get system parameters. The Modbus daemon acts as slave device. That means it accepts connections from a master (client) and sends out a response or sets some system related parameter in accordance with the given query.

The figure below is an example of the Modbus TCP window section and the table below provides information on the fields contained in that window:

[[File:{{{modbus_tcp_file}}}]]

Get Parameters

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Modbus parameters are held within registers. Each register contains 2 bytes of information. For simplification, the number of registers for storing numbers is 2 (4 bytes), while the number of registers for storing text information is 16 (32 bytes). The register numbers and corresponding system values are described in the table below:

{{Template: Networking_{{{name}}}_manual_modbus_modbus_tcp_get_parameters_table}}

Set Parameters

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The Modbus daemon can also set some device parameters. These parameters and explanations on how to use them are described in the table below:

{{Template: Networking_{{{name}}}_manual_modbus_modbus_tcp_set_parameters_table}}

* All ON/OFF commands only accept 0 and 1 values, which represent the following:

• 1 - ON
• 0 - OFF

Modbus TCP Master

A Modbus master device can request data from Modbus slaves. The Modbus TCP Master section is used to configure Modbus TCP slaves. To add a new slave, enter a custom name, slave's ID, IP address and port and click the "Add" button:

[[File:{{{file_add_new_slave}}}]]

Slave device configuration

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The figure below is an example of the Slave device configuration and the table below provides information on the fields contained in that section:

[[File:{{{file_slave_configuration}}}]]

Field name	Value	Description
Enabled	yes | no; Default: no	Turns communication with the slave device ON or OFF
Name	string; Default: none	Slave device custom name, used for easier management purposes
Slave ID	integer [1..247]; Default: none	Slave ID. Each slave in a network is assigned a unique identifier randging from 1 to 247. When the master requests data from a slave, the first byte it sends is the Slave ID
IP address	ip; Default: none	Slave device IP address
Port	integer [0..65535]; Default: none	Slave device Modbus TCP port
Period	integer [1..6400]; Default: none	Interval at which requests are sent to the slave device
Timeout	integer [1..30]; Default: none	Maximum response wait time

Modbus Data to Server

[[File:{{{file_add_new_sender}}}]]

[[File:{{{file_sender_configuration}}}]]

See also

[[Category:{{{name}}} WebUI]]