MSPM0 Modbus Library User’s Guide

1. Introduction

The MSPM0 Modbus Library provides a simple way to start development of Modbus applications using MSPM0 devices.

2. Modbus Library Features

This Library was developed in compliance with Modbus V1.2 specification

3. Modbus Example Usage

Two examples are given in the MSPM0 SDK demonstrating the MSPM0 as a Modbus Controller or Modbus Target

To test the Modbus controller and Modbus target examples, connect the UART pins of controller and target. Refer to code example readme for specefic pin configurations. Load the program to controller device and target device. The example serves the following commands

S.No	Command	Code	Description
1	Read discrete Inputs	0x02	To read the contents of discrete inputs.
2	Read coils	0x01	To read the contents of coils.
3	Write single coil	0x05	To write the content on a coil.
4	Write multiple coil	0x0F	To write the content on multiple coils.
5	Read input registers	0x04	To read the contents of input registers.
6	Read holding registers	0x03	To read the contents of holding registers.
7	Write single register	0x06	To write the content on a holding register.
8	Write multiple registers	0x10	To write the content on multiple holding registers.
9	Read/Write multiple registers	0x17	To simultaneously read and write multiple holding registers, write before read.
10	Mask write register	0x16	To write the content on a holding register based on and/or mask.
11	Read FIFO queue	0x18	Planned for future.
12	Read file record	0x14	Planned for future (example use case is in SDK with 1 file and 10 records).
13	Write file record	0x15	Planned for future (example use case is in SDK with 1 file and 10 records).
14	Read exception status	0x07	To read the exception status (1=exception occurred in last transaction, 0= No exception).
15	Diagnostic	0x08	Working depends on subfunction code.
16	Get comm event counter	0x0B	To get the total number of events that have occurred at the target side.
17	Get comm event log	0x0C	To get the event logs of all the events. Each event is a byte, with each bit having specific meaning, user can refer the official specification document of Modbus to get the exact matching of each bit.
18	Report Server ID	0x11	To get the server ID of the target, along with its status, whether it is on or it is off.

3.1 Supported Hardware

• LP_MSPM0G3507

4. Library Versions

• Version 1.00.00.00

  • SDK Release: 2.06.00.xx

  • Updates:

    • Initial release.