Modbus TCP/IP Client Write

Client device writes data to server device register(s) over TCP/IP network

Since R2021a

Add-On Required: This feature requires the Simulink Support Package for Raspberry Pi Hardware add-on.

• 

Libraries:
Simulink Support Package for Raspberry Pi Hardware / Network

Description

In the Modbus TCP/IP Client Write block, the client device writes data to the register(s) of the server device.

Simulink^® Support Package for Raspberry Pi^® Hardware supports the Modbus^® communication protocol over the TCP/IP network. The client and the server must be connected to the TCP/IP network for successful Modbus communication.

The client can perform either a read, write, or a read and write operation on the server register depending on the server register(s) type.

Register Type	Register Size	Operation Performed by Client
Coil	1-bit	Read and Write
Discrete Input	1-bit	Read
Holding Register	16-bit	Read and Write
Input Register	16-bit	Read

The client can perform either a read or a write operation (depending on the register type) on register(s) of a server device.

Ports

Input

Data — Input data

vector

The input to the block is the data that the client writes to the server register(s). Specify the input data as a N-by-1 vector, where N represents the number of registers on the server device.

• If you select the Coil or Discrete Input write operations, the client writes data to the server registers as a 1-bit write operation as Boolean data.

• If you select the Holding Register or Input Register write operations, the client writes data to the server registers as a 16-bit write operation as uint16 data.

Data Types: Boolean | uint16

Parameters

Server address — Unique IP address for server device

127.0.0.1 (default) | IP address

Enter the IP address of the server device to identify the server to which the client writes the data.

Function — Type of write operation

Write Coil (default) | Write Holding register | Write Multiple Coils | Write Multiple Holding registers

Select the type of write operation you want to perform on the server register(s). Specify any one of the following:

• Write Coil: Write data to the coil register address specified in the Coil Address parameter.

• Write Holding register: Write data to the holding register address specified in the Holding Register Address parameter.

• Write Multiple Coils: Write data to multiple coil registers depending on the values specified in the Coil Address and Number of Coils parameters.

• Write Multiple Holding registers: Write data to multiple holding registers depending on the values specified in the Holding Register Address and Number of Holding registers parameters.

Coil Address — Address of coil register

0 (default) | scalar

• To notify the client to write data to a specific coil register, specify the coil register address in this parameter. For example, for the client to write data to the coil register with the address 10, enter 10.

• To notify the client to write data to a group of coil registers, specify the address of the first coil register in the group. For example, for the client to write data to the coil registers with addresses ranging from 10 to 14, enter 10.

Dependencies

To enable this parameter, set Function to Write Coil.

Number of Coils — Number of coil registers to be written by client

1 (default) | scalar

Enter the number of coil registers to which you want the client to write the data. For example, for the client to write data to the coil registers with addresses ranging from 10 to 14, enter 5.

Dependencies

To enable this parameter, set Function to Write Multiple Coils.

Holding Register Address — Address of holding register

0 (default) | scalar

• To notify the client to write data to a specific holding register, specify the holding register address in this parameter. For example, for the client to write data to the holding register with the address 37, enter 37.

• To notify the client to write data to a group of holding registers, specify the address of the first holding register in the group. For example, for the client to write data to the holding registers with addresses ranging from 37 to 44, enter 37.

Dependencies

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

Number of Holding registers — Number of holding registers to be written by client

1 (default) | scalar

Enter the number of holding registers from which you want the client to write the data. For example, for the client to write data to the holding registers with addresses ranging from 37 to 44, enter 8.

Dependencies

To enable this parameter, set Function to Write Multiple Holding registers.

Version History

Introduced in R2021a