Systems and methods for a modbus command/response protocol

Patent metadata

Field	Value
Publication number	US-2026010317-A1
Application number	US-202519262612-A
Country	US
Kind code	A1
Filing date	Jul 8, 2025
Priority date	Jul 8, 2024
Publication date	Jan 8, 2026
Grant date	—

Abstract

Systems and methods for communication between a management system and a plurality of devices over a communication line are provided. One method includes the management system generating a Modbus packet comprising a block write command to a first contiguous array of registers of a device of the plurality of devices, collectively designated as a command buffer, where the block write command corresponds to a request for the device to perform an action, and a block read command to a second contiguous array of registers of the device, collectively designated as a response buffer. The method also includes the management system transmitting the Modbus packet over the communication line to the device and receiving data from the response buffer in response to the block read command, where the data is written into the response buffer by the device based on the request.

First claim

1 . A communication method for a management system of a control system including a plurality of devices in communication with the management system over a communication line, the method comprising:
the management system generating a Modbus packet comprising:
a block write command to a first contiguous array of registers of a device of the plurality of devices, collectively designated as a command buffer, wherein the block write command corresponds to a request for the device to perform an action, and
a block read command to a second contiguous array of registers of the device, collectively designated as a response buffer;
the management system transmitting the Modbus packet over the communication line to the device; and the management system receiving data from the response buffer in response to the block read command, the data written into the response buffer by the device based on the request.

2 . The communication method of claim 1 , wherein generating the Modbus packet further comprises mapping keywords of the request to single byte tokens.

3 . The communication method of claim 1 , wherein generating the Modbus packet further comprises encrypting contents of the block write command and the block read command into ciphertext.

4 . The communication method of claim 1 , wherein generating the Modbus packet further comprises incorporating a forward error correction field in a payload of the Modbus packet.

5 . The communication method of claim 1 , wherein generating the Modbus packet further comprises incorporating a macro into the block write command, such that the block write command corresponds to a list of requests for the device to perform multiple actions.

6 . The communication method of claim 1 , wherein generating the Modbus packet further comprises incorporating a device identifier associated with the device in a payload of the Modbus packet instead of a header of the Modbus packet.

7 . The communication method of claim 1 , wherein the management system transmitting the Modbus packet over the communication line to the device includes the management system transmitting the Modbus packet over an RS-485 communication line to the device.

8 . The communication method of claim 1 , wherein the management system transmitting the Modbus packet over the communication line to the device includes the management system transmitting the Modbus packet over a wireless communication line to the device.

9 . A communication method for a device within a control system comprising a plurality of devices in communication with a management system over a communication line, the method comprising:
the device receiving a Modbus packet from the management system over the communication line, the Modbus packet comprising:
a block write command to a first contiguous array of registers of the device, collectively designated as a command buffer, wherein the block write command corresponds to a request for the device to perform an action, and
a block read command to a second contiguous array of registers of the device, collectively designated as a response buffer;
the device interpreting the request based on data within the command buffer, including determining registers of the device associated with the request, the registers being outside of the first contiguous array of registers and the second contiguous array of registers; the device performing the request; and the device writing data into the response buffer based on performing the request, to be read by the management system.

10 . The communication method of claim 9 , wherein interpreting the request further comprises mapping single byte tokens within the data within the command buffer to keywords associated with the request.

11 . The communication method of claim 9 , wherein interpreting the request further comprises further comprises decrypting contents of the block write command and the block read command from ciphertext into plaintext.

12 . The communication method of claim 9 , wherein interpreting the request further comprises reading a macro in the block write command, and obtaining, from memory, a list of requests associated with the macro to perform multiple actions.

13 . The communication method of claim 1 , wherein interpreting the request further comprises determining that the request is for the device to perform the action based on a device identifier associated with the device in a payload of the Modbus packet instead of a header of the Modbus packet.

14 . The communication method of claim 9 , wherein the device receiving the Modbus packet from the management system over the communication line includes the device receiving the Modbus packet from the management system over an RS-485 communication line.

15 . The communication method of claim 9 , wherein the device receiving the Modbus packet from the management system over the communication line includes the device receiving the Modbus packet from the management system over a wireless communication line.

16 . A communication method for a device within a control system comprising a plurality of devices in communication with a management system over a communication line, the method comprising:
the device receiving a first Modbus packet from the management system over the communication line, the first Modbus packet comprising:
a first block write command to a first contiguous array of registers of the device, collectively designated as a command buffer, wherein the first block write command corresponds to a request for the device to perform an action, and
a first block read command to a second contiguous array of registers of the device, collectively designated as a response buffer;
the device writing first data into the response buffer, to be read by the management system through the first block read command, indicating that a response to the request is not yet available; the device processing the request based on data within the command buffer; the device performing the request; the device writing second data into the response buffer based on performing the request; and the device receiving a second Modbus packet from the management system over the communication line, the second Modbus packet comprising a second block read command from the response buffer.

17 . The communication method of claim 16 , wherein the response buffer includes a first response buffer and a second response buffer, wherein the device writing first data into the response buffer, to be read by the management system through the first block read command, indicating that the response to the request is not yet available comprises:
the device writing the first data into the first response buffer indicating that the response to the request is not yet available; and the device activating the first response buffer and deactivating the second response buffer so that the management system reads the first response buffer through the first block read command.

18 . The communication method of claim 17 , wherein the device writing the second data into the response buffer based on performing the request includes the device writing the second data into the second response buffer; and further comprising:
upon completion of the request, the device acting the second response buffer and deactivating the first response buffer so that the management system reads the second response buffer through the second block read command.

19 . The communication method of claim 18 , wherein the device writing the first data into the first response buffer indicating

Assignees

• Nvent Services Gmbh

Inventors

• Southwell David Thomas

Classifications

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F3/0656

  Data buffering arrangements · CPC title

• G06F3/0619

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F3/0659 Primary

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• H04L2012/4026

  Bus for use in automation systems · CPC title