Modbus TCP/IP Server Read

R2026b

Server device reads data from server device register over TCP/IP network

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Modbus TCP/IP Server Read block

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Libraries:
Raspberry Pi Blockset / Network

Description

In the Modbus TCP/IP Server Read block, the server device reads data from its registers. The server can read data from only one register per read operation.

Raspberry Pi^® Blockset supports the Modbus^® communication protocol over the TCP/IP network.

The server can perform read and write operation on these server register(s).

Register Type	Register Size
Coil	1-bit
Discrete Input	1-bit
Holding Register	16-bit
Input Register	16-bit

The server can perform either a read or a write operation on its registers.

Note

To generate C/C++ code for this block, you must have an Embedded Coder^® license.

Examples

MODBUS TCP/IP Communication Between Client and Server Devices Using Raspberry Pi Hardware

Use Raspberry Pi® Blockset to implement MODBUS® TCP/IP communication between MODBUS client and server devices. It also shows how to communicate between the two devices in four modes of operation, Client Read, Client Write, Server Read, and Server Write.

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Ports

Output

Data — Output data

scalar

The block outputs the data read by the server device from its register as a 1-bit scalar.

• If you select the Coil or Discrete Input read operations, the server reads its registers as a 1-bit read operation. The block outputs the read data as Boolean data.

• If you select the Holding Register or Input Register read operations, the server reads its registers as a 16-bit read operation. The block outputs the read data as uint16 data.

Data Types: Boolean | uint16

Status — Status of read operation

0 | 1

The block outputs the status of the server read operation on the server register.

• 0: Indicates an unsuccessful read operation, which means that the data received on the data port is invalid.

• 1: Indicates a successful read operation, which means that the data received on the data port is valid.

Data Types: uint8

Parameters

Function — Type of read operation

Read Coil (default) | Read Discrete Input | Read Holding register | Read Input register

Select the type of read operation you want to perform on the server register. Specify any one of the following:

• Read Coil: Read data from the coil register address specified in the Coil Address parameter.

• Read Discrete Input: Read data from the discrete input register address specified in the Discrete Input Address parameter.

• Read Holding register: Read data from the holding register address specified in the Holding Register Address parameter.

• Read Input register: Read data from the input register address specified in the Input Register Address parameter.

Coil Address — Address of coil register

0 (default) | scalar

To notify the server to read data from a specific coil register, specify the coil register address in this parameter. For example, for the server to read data from the coil register with the address 10, enter 10.

Dependencies

To enable this parameter, set Function to Read Coil.

Discrete Input Address — Address of discrete input register

0 (default) | scalar

To notify the server to read data from a specific discrete input register, specify the discrete input register address in this parameter. For example, for the server to read data from the discrete input register with the address 80, enter 80.

Dependencies

To enable this parameter, set Function to Read Discrete Input.

Holding Register Address — Address of holding register

0 (default) | scalar

To notify the server to read data from a specific holding register, specify the holding register address in this parameter. For example, for the server to read data from the holding register with the address 37, enter 37.

Dependencies

To enable this parameter, set Function to Read Holding register.

Input Register Address — Address of input register

0 (default) | scalar

To notify the server to read data from a specific input register, specify the input register address in this parameter. For example, for the server to read data from the input register with the address 25, enter 25.

Dependencies

To enable this parameter, set Function to Read Input register.

Sample Time — Time interval at which server reads data

0.1 (default) | scalar

Enter the time interval (in seconds) at which the server reads data from its register.

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"raspberrypiNetworklib/Modbus TCP//IP Server Read"

Example: add_block("raspberrypiNetworklib/Modbus TCP//IP Server Read","myModel/myBlock",MakeNameUnique="on")

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

To generate C/C++ code for this block, you must have an Embedded Coder license. For more information on selecting the right product stack according to your development goals, see Product Stack for Raspberry Pi Blockset.

Version History

Introduced in R2021a