Modbus TCP/IP Client Read
Client device reads data from 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 Read block, the client device reads data from 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 |
Ports
Output
Data — Output data
vector
The block outputs the data read by the client from the server device register(s) 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 read operations, the client reads the server 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 client reads the server 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 client read operation on the server device 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
Server address — Unique IP address for server device
127.0.0.1
(default) | IP address
Enter the IP address of the server device. The client reads data from this server device.
Function — Type of client read operation
Read Coil
(default) | Read Discrete input
| Read Holding register
| Read Input register
| Read Multiple Coils
| Read Multiple Discrete inputs
| Read Multiple Holding registers
| Read Multiple Input registers
Select the type of read operation you want to perform on the server register(s). Specify any one of these:
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.Read Multiple Coils
: Read data from multiple coil registers depending on the values specified in the Coil Address and Number of Coils parameters.Read Multiple Discrete inputs
: Read data from multiple discrete input registers depending on the values specified in the Discrete Input Address and Number of Discrete Inputs parameters.Read Multiple Holding registers
: Read data from multiple holding registers depending on the values specified in the Holding Register Address and Number of Holding registers parameters.Read Multiple Input registers
: Read data from multiple input registers depending on the values specified in the Input Register Address and Number of Input registers parameters.
Coil Address — Address of coil register
0
(default) | scalar
To notify the client to read data from a specific coil register, specify the coil
register address in this parameter. For example, for the client to read data from the
coil register with the address 10
, enter
10
.
To notify the client to read data from a group of coil registers, specify the
address of the first coil register in the group. For example, for the client to read
data from the coil registers with addresses ranging from 10
to
14
, enter 10
.
Dependencies
To enable this parameter, set Function to Read
Coil
.
Number of Coils — Number of coil registers to be read by client
1
(default) | scalar
Enter the number of coil registers from which you want the client to read the data.
For example, for the client to read data from the coil registers with addresses ranging
from 10
to 14
, enter 5
.
Dependencies
To enable this parameter, set Function to Read
Multiple Coils
.
Discrete Input Address — Address of discrete input register
0
(default) | scalar
To notify the client to read data from a specific discrete input register, specify
the discrete input register address in this parameter. For example, for the client to
read data from the discrete input register with the address 80
, enter
80
.
To notify the client to read data from a group of discrete input registers, specify
the address of the first discrete input register in the group. For example, for the
client to read data from the discrete input registers with addresses ranging from
80
to 89
, enter 80
.
Dependencies
To enable this parameter, set Function to Read
Discrete input
.
Number of Discrete Inputs — Number of discrete input registers to be read by client
1
(default) | scalar
Enter the number of discrete input registers from which you want the client to read
the data. For example, for the client to read data from the discrete input registers
with addresses ranging from 80
to 89
, enter
10
.
Dependencies
To enable this parameter, set Function to Read
Multiple Discrete inputs
.
Holding Register Address — Address of holding register
0
(default) | scalar
To notify the client to read data from a specific holding register, specify the
holding register address in this parameter. For example, for the client to read data
from the holding register with the address 37
, enter
37
.
To notify the client to read data from a group of holding registers, specify the
address of the first holding register in the group. For example, for the client to read
data from the holding registers with addresses ranging from 37
to
44
, enter 37
.
Dependencies
To enable this parameter, set Function to Read
Holding register
.
Number of Holding registers — Number of holding registers to be read by client
1
(default) | scalar
Enter the number of holding registers from which you want the client to read the
data. For example, for the client to read data from the holding registers with addresses
ranging from 37
to 44
, enter
8
.
Dependencies
To enable this parameter, set Function to Read
Multiple Holding registers
.
Input Register Address — Address of input register
0
(default) | scalar
To notify the client to read data from a specific input register, specify the input register address in this parameter. For example, for the client to read data from the input register with the address
25
, enter25
.To notify the client to read data from a group of input registers, specify the address of the first input register in the group. For example, for the client to read data from the input registers with addresses ranging from
25
to26
, enter25
.
Dependencies
To enable this parameter, set Function to Read
Input register
.
Number of Input registers — Number of input registers to be read by client
1
(default) | scalar
Enter the number of input registers from which you want the client to read the data.
For example, for the client to read data from the input registers with addresses ranging
from 25
to 26
, enter 2
.
Dependencies
To enable this parameter, set Function to Read
Multiple Input registers
.
Sample Time — Time interval at which client reads data
0.1
(default) | scalar
Enter the time interval (in seconds) at which the client reads data from the server device register(s).
Version History
Introduced in R2021a
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