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code: 添加modbus代码

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code/09.extra/modbus/mb_example_common/CMakeLists.txt
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# The following five lines of boilerplate have to be in your project's
# CMakeLists in this exact order for cmake to work correctly
cmake_minimum_required(VERSION 3.16)
idf_component_register(SRCS "modbus_params.c"
INCLUDE_DIRS "include")
code/09.extra/modbus/mb_example_common/README.md
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# Modbus Example Common
This directory contains component that is common for Modbus master and slave examples. The component defines Modbus parameters that are shared between examples and provide code that you can copy and adapt into your own projects.
For more information please refer to Modbus example README.md files located in the folders:
* `examples/protocols/modbus/serial/mb_master` Modbus serial master implementation (RTU and ASCII)
* `examples/protocols/modbus/serial/mb_slave` Modbus serial slave implementation (RTU and ASCII)
* `examples/protocols/modbus/serial/mb_master` Modbus serial master implementation (RTU and ASCII)
* `examples/protocols/modbus/tcp/mb_tcp_slave` Modbus serial slave implementation (TCP)
* `examples/protocols/modbus/tcp/mb_tcp_master` Modbus serial master implementation (TCP)
code/09.extra/modbus/mb_example_common/include/modbus_params.h
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/*
* SPDX-FileCopyrightText: 2016-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
/*=====================================================================================
* Description:
* The Modbus parameter structures used to define Modbus instances that
* can be addressed by Modbus protocol. Define these structures per your needs in
* your application. Below is just an example of possible parameters.
*====================================================================================*/
#ifndef _DEVICE_PARAMS
#define _DEVICE_PARAMS
#include <stdint.h>
// This file defines structure of modbus parameters which reflect correspond modbus address space
// for each modbus register type (coils, discreet inputs, holding registers, input registers)
#pragma pack(push, 1)
typedef struct
{
uint8_t discrete_input0:1;
uint8_t discrete_input1:1;
uint8_t discrete_input2:1;
uint8_t discrete_input3:1;
uint8_t discrete_input4:1;
uint8_t discrete_input5:1;
uint8_t discrete_input6:1;
uint8_t discrete_input7:1;
uint8_t discrete_input_port1;
uint8_t discrete_input_port2;
} discrete_reg_params_t;
#pragma pack(pop)
#pragma pack(push, 1)
typedef struct
{
uint8_t coils_port0;
uint8_t coils_port1;
uint8_t coils_port2;
} coil_reg_params_t;
#pragma pack(pop)
#pragma pack(push, 1)
typedef struct
{
float input_data0; // 0
float input_data1; // 2
float input_data2; // 4
float input_data3; // 6
uint16_t data[150]; // 8 + 150 = 158
float input_data4; // 158
float input_data5;
float input_data6;
float input_data7;
uint16_t data_block1[150];
} input_reg_params_t;
#pragma pack(pop)
#pragma pack(push, 1)
typedef struct
{
float holding_data0;
float holding_data1;
float holding_data2;
float holding_data3;
uint16_t test_regs[150];
float holding_data4;
float holding_data5;
float holding_data6;
float holding_data7;
} holding_reg_params_t;
#pragma pack(pop)
extern holding_reg_params_t holding_reg_params;
extern input_reg_params_t input_reg_params;
extern coil_reg_params_t coil_reg_params;
extern discrete_reg_params_t discrete_reg_params;
#endif // !defined(_DEVICE_PARAMS)
code/09.extra/modbus/mb_example_common/modbus_params.c
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/*
* SPDX-FileCopyrightText: 2016-2021 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
/*=====================================================================================
* Description:
* C file to define parameter storage instances
*====================================================================================*/
#include "modbus_params.h"
// Here are the user defined instances for device parameters packed by 1 byte
// These are keep the values that can be accessed from Modbus master
holding_reg_params_t holding_reg_params = { 0 };
input_reg_params_t input_reg_params = { 0 };
coil_reg_params_t coil_reg_params = { 0 };
discrete_reg_params_t discrete_reg_params = { 0 };
code/09.extra/modbus/serial/README.md
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# Modbus Master-Slave Example
## Overview
These two projects illustrate the communication between Modbus master and slave device in the segment.
Master initializes Modbus interface driver and then reads parameters from slave device in the segment.
After several successful read attempts slave sets the alarm relay (end of test condition).
Once master reads the alarm it stops communication and destroy driver.
The examples:
* `examples/protocols/modbus/serial/mb_master` - Modbus serial master ASCII/RTU
* `examples/protocols/modbus/serial/mb_slave` - Modbus serial slave ASCII/RTU
See README.md for each individual project for more information.
## How to use example
### Hardware Required
This example can be run on any commonly available ESP32 development board.
The master and slave boards should be connected to each other through the RS485 interface line driver.
See the connection schematic in README.md files of each example.
### Configure the project
This example test requires communication mode setting for master and slave be the same and slave address set to 1.
Please refer to README.md files of each example project for more information.
## About common_component in this example
The folder "mb_example_common" includes definitions of parameter structures for master and slave device (both projects share the same parameters).
However, currently it is for example purpose only and can be modified for particular application.
## Example Output
Example of Slave output:
```
I (343) SLAVE_TEST: Modbus slave stack initialized.
I (343) SLAVE_TEST: Start modbus test...
I (81463) SLAVE_TEST: HOLDING READ (81150420 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2868, SIZE:6
I (82463) SLAVE_TEST: HOLDING READ (82150720 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2868, SIZE:6
I (83573) SLAVE_TEST: HOLDING READ (83260630 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2868, SIZE:6
I (84603) SLAVE_TEST: HOLDING READ (84290530 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2868, SIZE:6
I (85703) SLAVE_TEST: HOLDING READ (85396692 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2868, SIZE:6
```
Example of Modbus Master output:
```
I (399) MASTER_TEST: Modbus master stack initialized...
I (499) MASTER_TEST: Start modbus test...
I (549) MASTER_TEST: Characteristic #0 Data_channel_0 (Volts) value = 1.230000 (0x3f9d70a4) read successful.
I (629) MASTER_TEST: Characteristic #1 Humidity_1 (%rH) value = 12.100000 (0x4141999a) read successful.
I (709) MASTER_TEST: Characteristic #2 Temperature_1 (C) value = 3.560000 (0x4063d70a) read successful.
I (769) MASTER_TEST: Characteristic #3 Humidity_2 (%rH) value = 23.400000 (0x41bb3333) read successful.
I (829) MASTER_TEST: Characteristic #4 Temperature_2 (C) value = 5.890000 (0x40bc7ae1) read successful.
I (889) MASTER_TEST: Characteristic #5 Humidity_3 (%rH) value = 34.500000 (0x420a0000) read successful.
E (949) MB_CONTROLLER_MASTER: mbc_master_get_parameter(111): SERIAL master get parameter failure error=(0x108) (ESP_ERR_INVALID_RESPONSE).
E (949) MASTER_TEST: Characteristic #6 (RelayP1) read fail, err = 264 (ESP_ERR_INVALID_RESPONSE).
E (1029) MB_CONTROLLER_MASTER: mbc_master_get_parameter(111): SERIAL master get parameter failure error=(0x108) (ESP_ERR_INVALID_RESPONSE).
E (1029) MASTER_TEST: Characteristic #7 (RelayP2) read fail, err = 264 (ESP_ERR_INVALID_RESPONSE).
```
## Troubleshooting
If the examples do not work as expected and slave and master boards are not able to communicate correctly it is possible to find the reason for errors.
The most important errors are described in master example output and formatted as below:
```
E (1692332) MB_CONTROLLER_MASTER: mbc_master_get_parameter(111): SERIAL master get parameter failure error=(0x107) (ESP_ERR_TIMEOUT).
```
ESP_ERR_TIMEOUT (0x107) - Modbus slave device does not respond during configured timeout. Check the connection and ability for communication using uart_echo_rs485 example or increase
Kconfig value CONFIG_FMB_MASTER_TIMEOUT_MS_RESPOND (CONFIG_FMB_SERIAL_ASCII_TIMEOUT_RESPOND_MS).
ESP_ERR_NOT_SUPPORTED (0x106), ESP_ERR_INVALID_RESPONSE (0x108) - Modbus slave device does not support requested command or register and sent exeption response.
ESP_ERR_INVALID_STATE (0x103) - Modbus stack is not configured correctly or can't work correctly due to critical failure.
code/09.extra/modbus/serial/mb_master/CMakeLists.txt
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# The following lines of boilerplate have to be in your project's CMakeLists
# in this exact order for cmake to work correctly
cmake_minimum_required(VERSION 3.16)
include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(modbus_master)
code/09.extra/modbus/serial/mb_master/README.md
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| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-P4 | ESP32-S2 | ESP32-S3 |
| ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | -------- | -------- |
# Modbus Master Example
This example demonstrates using of FreeModbus stack port implementation for ESP32 as a master device.
This implementation is able to read/write values of slave devices connected into Modbus segment. All parameters to be accessed are defined in data dictionary of the modbus master example source file.
The values represented as characteristics with its name and characteristic CID which are linked into registers of slave devices connected into Modbus segment.
The example implements simple control algorithm and checks parameters from slave device and gets alarm (relay in the slave device) when value of holding_data0 parameter exceeded limit.
The instances for the modbus parameters are common for master and slave examples and located in `examples/protocols/modbus/mb_example_common` folder.
Example parameters definition:
--------------------------------------------------------------------------------------------------
| Slave Address | Characteristic ID | Characteristic name | Description |
|---------------------|----------------------|----------------------|----------------------------|
| MB_DEVICE_ADDR1 | CID_INP_DATA_0, | Data_channel_0 | Data channel 1 |
| MB_DEVICE_ADDR1 | CID_HOLD_DATA_0, | Humidity_1 | Humidity 1 |
| MB_DEVICE_ADDR1 | CID_INP_DATA_1 | Temperature_1 | Sensor temperature |
| MB_DEVICE_ADDR1 | CID_HOLD_DATA_1, | Humidity_2 | Humidity 2 |
| MB_DEVICE_ADDR1 | CID_INP_DATA_2 | Temperature_2 | Ambient temperature |
| MB_DEVICE_ADDR1 | CID_HOLD_DATA_2 | Humidity_3 | Humidity 3 |
| MB_DEVICE_ADDR1 | CID_RELAY_P1 | RelayP1 | Alarm Relay outputs on/off |
| MB_DEVICE_ADDR1 | CID_RELAY_P2 | RelayP2 | Alarm Relay outputs on/off |
--------------------------------------------------------------------------------------------------
Note: The Slave Address is the same for all parameters for example test but it can be changed in the ```Example Data (Object) Dictionary``` table of master example to address parameters from other slaves.
The Kconfig ```Modbus slave address``` - CONFIG_MB_SLAVE_ADDR parameter in slave example can be configured to create Modbus multi slave segment.
Simplified Modbus connection schematic for example test:
```
MB_DEVICE_ADDR1
------------- -------------
| | RS485 network | |
| Slave 1 |---<>--+---<>---| Master |
| | | |
------------- -------------
```
Modbus multi slave segment connection schematic:
```
MB_DEVICE_ADDR1
-------------
| |
| Slave 1 |---<>--+
| | |
------------- |
MB_DEVICE_ADDR2 |
------------- | -------------
| | | | |
| Slave 2 |---<>--+---<>---| Master |
| | | | |
------------- | -------------
MB_DEVICE_ADDR3 |
------------- RS485 network
| | |
| Slave 3 |---<>--+
| |
-------------
```
## Hardware required :
Option 1:
PC (Modbus Slave app) + USB Serial adapter connected to USB port + RS485 line drivers + ESP32 based board
Option 2:
Several ESP32 boards flashed with modbus_slave example software to represent slave device with specific slave address (See CONFIG_MB_SLAVE_ADDR). The slave addresses for each board have to be configured as defined in "connection schematic" above.
One ESP32 board flashed with modbus_master example. All the boards require connection of RS485 line drivers (see below).
The MAX485 line driver is used as an example below but other similar chips can be used as well.
RS485 example circuit schematic for connection of master and slave devices into segment:
```
VCC ---------------+ +--------------- VCC
| |
+-------x-------+ +-------x-------+
RXD <------| RO | DIFFERENTIAL | RO|-----> RXD
| B|---------------|B |
TXD ------>| DI MAX485 | \ / | MAX485 DI|<----- TXD
ESP32 BOARD | | RS-485 side | | External PC (emulator) with USB to serial or
RTS --+--->| DE | / \ | DE|---+ ESP32 BOARD (slave)
| | A|---------------|A | |
+----| /RE | PAIR | /RE|---+-- RTS
+-------x-------+ +-------x-------+
| |
--- ---
Modbus Master device Modbus Slave device
```
## How to setup and use an example:
### Configure the application
Start the command below to setup configuration:
```
idf.py menuconfig
```
Configure the UART pins used for modbus communication using and table below.
Define the communication mode parameter for master and slave in Kconfig - CONFIG_MB_COMM_MODE (must be the same for master and slave devices in one segment).
Configure the slave address for each slave in the Modbus segment (the CONFIG_MB_SLAVE_ADDR in Kconfig).
```
------------------------------------------------------------------------------------------------------------------------------
| UART Interface | #define | Default pins for | Default pins for | External RS485 Driver Pin |
| | | ESP32 (C6) | ESP32-S2 (S3, C3, C2, H2) | |
| ----------------------|--------------------|-----------------------|---------------------------|---------------------------|
| Transmit Data (TxD) | CONFIG_MB_UART_TXD | GPIO23 | GPIO9 | DI |
| Receive Data (RxD) | CONFIG_MB_UART_RXD | GPIO22 | GPIO8 | RO |
| Request To Send (RTS) | CONFIG_MB_UART_RTS | GPIO18 | GPIO10 | ~RE/DE |
| Ground | n/a | GND | GND | GND |
------------------------------------------------------------------------------------------------------------------------------
```
Note: Each target chip has different GPIO pins available for UART connection. Please refer to UART documentation for selected target for more information.
Connect a USB-to-RS485 adapter to a computer, then connect the adapter's A/B output lines with the corresponding A/B output lines of the RS485 line driver connected to the ESP32 chip (see figure above).
The communication parameters of Modbus stack allow to configure it appropriately but usually it is enough to use default settings.
See the help string of parameters for more information.
### Setup external Modbus slave devices or emulator
Option 1:
Configure the external Modbus master software according to port configuration parameters used in the example. The Modbus Slave application can be used with this example to emulate slave devices with its parameters. Use official documentation for software to setup emulation of slave devices.
Option 2:
Other option is to have the modbus_slave example application flashed into ESP32 based board and connect boards together as showed on the Modbus connection schematic above. See the Modbus slave API documentation to configure communication parameters and slave addresses as defined in "Example parameters definition" table above.
### Build and flash software of master device
Build the project and flash it to the board, then run monitor tool to view serial output:
```
idf.py -p PORT flash monitor
```
(To exit the serial monitor, type ``Ctrl-]``.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
## Example Output
Example output of the application:
```
I (9035) MASTER_TEST: Characteristic #0 Data_channel_0 (Volts) value = 1.120000 (0x3f8f5c29) read successful.
I (9045) MASTER_TEST: Characteristic #1 Humidity_1 (%rH) value = 5.539999 (0x40b147ac) read successful.
I (9045) MASTER_TEST: Characteristic #2 Temperature_1 (C) value = 2.340000 (0x4015c28f) read successful.
I (9055) MASTER_TEST: Characteristic #3 Humidity_2 (%rH) value = 2.560000 (0x4023d70a) read successful.
I (9065) MASTER_TEST: Characteristic #4 Temperature_2 (C) value = 3.560000 (0x4063d70a) read successful.
I (9075) MASTER_TEST: Characteristic #5 Humidity_3 (%rH) value = 3.780000 (0x4071eb85) read successful.
I (9085) MASTER_TEST: Characteristic #6 RelayP1 (on/off) value = OFF (0x55) read successful.
I (9095) MASTER_TEST: Characteristic #7 RelayP2 (on/off) value = OFF (0xaa) read successful.
I (9605) MASTER_TEST: Characteristic #0 Data_channel_0 (Volts) value = 1.120000 (0x3f8f5c29) read successful.
I (9615) MASTER_TEST: Characteristic #1 Humidity_1 (%rH) value = 5.739999 (0x40b7ae12) read successful.
I (9615) MASTER_TEST: Characteristic #2 Temperature_1 (C) value = 2.340000 (0x4015c28f) read successful.
I (9625) MASTER_TEST: Characteristic #3 Humidity_2 (%rH) value = 2.560000 (0x4023d70a) read successful.
I (9635) MASTER_TEST: Characteristic #4 Temperature_2 (C) value = 3.560000 (0x4063d70a) read successful.
I (9645) MASTER_TEST: Characteristic #5 Humidity_3 (%rH) value = 3.780000 (0x4071eb85) read successful.
I (9655) MASTER_TEST: Characteristic #6 RelayP1 (on/off) value = OFF (0x55) read successful.
I (9665) MASTER_TEST: Characteristic #7 RelayP2 (on/off) value = ON (0xff) read successful.
I (10175) MASTER_TEST: Alarm triggered by cid #7.
I (10175) MASTER_TEST: Destroy master...
```
The example reads the characteristics from slave device(s), while alarm is not triggered in the slave device (See the "Example parameters definition"). The output line describes Timestamp, Cid of characteristic, Characteristic name (Units), Characteristic value (Hex).
code/09.extra/modbus/serial/mb_master/main/CMakeLists.txt
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set(PROJECT_NAME "modbus_master")
idf_component_register(SRCS "master.c"
INCLUDE_DIRS ".")
code/09.extra/modbus/serial/mb_master/main/Kconfig.projbuild
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menu "Modbus Example Configuration"
orsource "$IDF_PATH/examples/common_components/env_caps/$IDF_TARGET/Kconfig.env_caps"
config MB_UART_PORT_ONE
bool
default y
depends on (ESP_CONSOLE_UART_NUM !=1) && (SOC_UART_NUM > 1)
config MB_UART_PORT_TWO
bool
default y
depends on (ESP_CONSOLE_UART_NUM !=2) && (SOC_UART_NUM > 2)
config MB_UART_PORT_NUM
int "UART port number"
range 0 2 if MB_UART_PORT_TWO
default 2 if MB_UART_PORT_TWO
range 0 1 if MB_UART_PORT_ONE
default 1 if MB_UART_PORT_ONE
help
UART communication port number for Modbus example.
config MB_UART_BAUD_RATE
int "UART communication speed"
range 1200 115200
default 115200
help
UART communication speed for Modbus example.
config MB_UART_RXD
int "UART RXD pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_IN_RANGE_MAX
default 22 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6 || IDF_TARGET_ESP32P4
default 8 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART RX pin. See UART documentation for more information
about available pin numbers for UART.
config MB_UART_TXD
int "UART TXD pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_OUT_RANGE_MAX
default 23 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6 || IDF_TARGET_ESP32P4
default 9 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART TX pin. See UART documentation for more information
about available pin numbers for UART.
config MB_UART_RTS
int "UART RTS pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_OUT_RANGE_MAX
default 20 if IDF_TARGET_ESP32P4
default 18 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6
default 10 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART RTS pin. This pin is connected to
~RE/DE pin of RS485 transceiver to switch direction.
See UART documentation for more information about available pin
numbers for UART.
choice MB_COMM_MODE
prompt "Modbus communication mode"
default MB_COMM_MODE_RTU if CONFIG_FMB_COMM_MODE_RTU_EN
help
Selection of Modbus communication mode option for Modbus.
config MB_COMM_MODE_RTU
bool "RTU mode"
depends on FMB_COMM_MODE_RTU_EN
config MB_COMM_MODE_ASCII
bool "ASCII mode"
depends on FMB_COMM_MODE_ASCII_EN
endchoice
endmenu
code/09.extra/modbus/serial/mb_master/main/idf_component.yml
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dependencies:
idf: ">=4.1"
espressif/esp-modbus:
version: "^1.0"
mb_example_common:
path: ${IDF_PATH}/examples/protocols/modbus/mb_example_common
code/09.extra/modbus/serial/mb_master/main/master.c
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code/09.extra/modbus/serial/mb_master/sdkconfig.defaults
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#
# Modbus configuration
#
CONFIG_FMB_TIMER_PORT_ENABLED=n
CONFIG_MB_COMM_MODE_ASCII=y
CONFIG_MB_UART_BAUD_RATE=115200
CONFIG_FMB_MASTER_DELAY_MS_CONVERT=200
CONFIG_FMB_MASTER_TIMEOUT_MS_RESPOND=400
CONFIG_FMB_TIMER_USE_ISR_DISPATCH_METHOD=y
code/09.extra/modbus/serial/mb_slave/CMakeLists.txt
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# The following lines of boilerplate have to be in your project's CMakeLists
# in this exact order for cmake to work correctly
cmake_minimum_required(VERSION 3.16)
include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(modbus_slave)
code/09.extra/modbus/serial/mb_slave/README.md
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| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-P4 | ESP32-S2 | ESP32-S3 |
| ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | -------- | -------- |
# Modbus Slave Example
This example demonstrates using the port of the FreeModbus stack on an ESP32 target where the ESP32 target is operating as a network slave. The example allows an external Modbus host to read/write device parameters on the ESP32 target using the Modbus protocol. The parameters accessible through Modbus are located in `mb_example_common/modbus_params.h\c` source/header files that users can update to add/remove their own custom parameters.
These are represented in structures `holding_reg_params`, `input_reg_params`, `coil_reg_params`, `discrete_reg_params` for holding registers, input parameters, coils and discrete inputs accordingly. The app_main application demonstrates how to setup Modbus stack and use notifications about parameters change from host system.
The FreeModbus stack located in `components/freemodbus` folder and contains the `/port` folder where the stack's port to the ESP32 is situated. There are some parameters of the port that can be configured in KConfig file to start stack correctly (See description below for more information).
The slave example uses shared parameter structures defined in `examples/protocols/modbus/mb_example_common` folder.
## Hardware required :
Option 1:
PC + USB Serial adapter connected to USB port + RS485 line drivers + ESP32 based board.
The MAX485 line driver is used as an example below but other similar chips can be used as well.
Option 2:
The modbus_master example application configured as described in its README.md file and flashed into ESP32 based board.
Note: The ```Example Data (Object) Dictionary``` in the modbus_master example can be edited to address parameters from other slaves connected into Modbus segment.
RS485 example circuit schematic:
```
VCC ---------------+ +--------------- VCC
| |
+-------x-------+ +-------x-------+
RXD <------| RO | DIFFERENTIAL | RO|-----> RXD
| B|---------------|B |
TXD ------>| DI MAX485 | \ / | MAX485 DI|<----- TXD
ESP32 board | | RS-485 side | | Modbus master
RTS --+--->| DE | / \ | DE|---+
| | A|---------------|A | |
+----| /RE | PAIR | /RE|---+-- RTS
+-------x--------+ +-------x-------+
| |
--- ---
```
## How to setup and use an example:
### Configure the application
Start the command below to show the configuration menu:
```
idf.py menuconfig
```
Select Modbus Example Configuration menu item.
Configure the UART pins used for modbus communication using the command and table below.
```
------------------------------------------------------------------------------------------------------------------------------
| UART Interface | #define | Default pins for | Default pins for | External RS485 Driver Pin |
| | | ESP32 (C6) | ESP32-S2 (S3, C3, C2, H2) | |
| ----------------------|--------------------|-----------------------|---------------------------|---------------------------|
| Transmit Data (TxD) | CONFIG_MB_UART_TXD | GPIO23 | GPIO9 | DI |
| Receive Data (RxD) | CONFIG_MB_UART_RXD | GPIO22 | GPIO8 | RO |
| Request To Send (RTS) | CONFIG_MB_UART_RTS | GPIO18 | GPIO10 | ~RE/DE |
| Ground | n/a | GND | GND | GND |
------------------------------------------------------------------------------------------------------------------------------
```
Note: Each target chip has different GPIO pins available for UART connection. Please refer to UART documentation for selected target for more information.
Define the ```Modbus communiction mode``` for slave in Kconfig - CONFIG_MB_COMM_MODE (must be the same for master and slave application).
Set ```Modbus slave address``` for the example application (by default for example script is set to 1).
The communication parameters of freemodbus stack (Component config->Modbus configuration) allow to configure it appropriately but usually it is enough to use default settings.
See the help strings of parameters for more information.
### Setup external Modbus master software
Option 1:
Configure the external Modbus master software according to port configuration parameters used in application.
As an example the Modbus Poll application can be used with this example.
Option 2:
Setup ESP32 based board and set modbus_master example configuration as described in its README.md file.
Setup one or more slave boards with different slave addresses and connect them into the same Modbus segment (See configuration above).
Note: The ```Modbus communiction mode``` parameter must be the same for master and slave example application to be able to communicate with each other.
### Build and flash software
Build the project and flash it to the board, then run monitor tool to view serial output:
```
idf.py -p PORT flash monitor
```
(To exit the serial monitor, type ``Ctrl-]``.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
## Example Output
Example output of the application:
```
I (13941) SLAVE_TEST: INPUT READ (13651163 us), ADDR:1, TYPE:8, INST_ADDR:0x3ffb2fd0, SIZE:2
I (13951) SLAVE_TEST: HOLDING READ (13656431 us), ADDR:1, TYPE:2, INST_ADDR:0x3ffb2fe0, SIZE:2
I (13961) SLAVE_TEST: INPUT READ (13665877 us), ADDR:3, TYPE:8, INST_ADDR:0x3ffb2fd4, SIZE:2
I (13971) SLAVE_TEST: HOLDING READ (13676010 us), ADDR:3, TYPE:2, INST_ADDR:0x3ffb2fe4, SIZE:2
I (13981) SLAVE_TEST: INPUT READ (13686130 us), ADDR:5, TYPE:8, INST_ADDR:0x3ffb2fd8, SIZE:2
I (13991) SLAVE_TEST: HOLDING READ (13696267 us), ADDR:5, TYPE:2, INST_ADDR:0x3ffb2fe8, SIZE:2
I (14001) SLAVE_TEST: COILS READ (13706331 us), ADDR:0, TYPE:32, INST_ADDR:0x3ffb2fcc, SIZE:8
I (14001) SLAVE_TEST: Modbus controller destroyed.
```
The output lines describe type of operation, its timestamp, modbus address, access type, storage address in parameter structure and number of registers accordingly.
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set(PROJECT_NAME "modbus_slave")
idf_component_register(SRCS "slave.c"
INCLUDE_DIRS ".")
code/09.extra/modbus/serial/mb_slave/main/Kconfig.projbuild
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menu "Modbus Example Configuration"
orsource "$IDF_PATH/examples/common_components/env_caps/$IDF_TARGET/Kconfig.env_caps"
config MB_UART_PORT_ONE
bool
default y
depends on (ESP_CONSOLE_UART_NUM !=1) && (SOC_UART_NUM > 1)
config MB_UART_PORT_TWO
bool
default y
depends on (ESP_CONSOLE_UART_NUM !=2) && (SOC_UART_NUM > 2)
config MB_UART_PORT_NUM
int "UART port number"
range 0 2 if MB_UART_PORT_TWO
default 2 if MB_UART_PORT_TWO
range 0 1 if MB_UART_PORT_ONE
default 1 if MB_UART_PORT_ONE
help
UART communication port number for Modbus example.
config MB_UART_BAUD_RATE
int "UART communication speed"
range 1200 115200
default 115200
help
UART communication speed for Modbus example.
config MB_UART_RXD
int "UART RXD pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_IN_RANGE_MAX
default 22 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6 || IDF_TARGET_ESP32P4
default 8 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART RX pin. See UART documentation for more information
about available pin numbers for UART.
config MB_UART_TXD
int "UART TXD pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_OUT_RANGE_MAX
default 23 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6 || IDF_TARGET_ESP32P4
default 9 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART TX pin. See UART documentation for more information
about available pin numbers for UART.
config MB_UART_RTS
int "UART RTS pin number"
range ENV_GPIO_RANGE_MIN ENV_GPIO_OUT_RANGE_MAX
default 20 if IDF_TARGET_ESP32P4
default 18 if IDF_TARGET_ESP32 || IDF_TARGET_ESP32C6
default 10 if IDF_TARGET_ESP32S2 || IDF_TARGET_ESP32S3 || IDF_TARGET_ESP32C3 ||\
IDF_TARGET_ESP32C2 || IDF_TARGET_ESP32H2
help
GPIO number for UART RTS pin. This pin is connected to
~RE/DE pin of RS485 transceiver to switch direction.
See UART documentation for more information about available pin
numbers for UART.
choice MB_COMM_MODE
prompt "Modbus communication mode"
default MB_COMM_MODE_RTU if CONFIG_FMB_COMM_MODE_RTU_EN
help
Selection of Modbus communication mode option for Modbus.
config MB_COMM_MODE_RTU
bool "RTU mode"
depends on FMB_COMM_MODE_RTU_EN
config MB_COMM_MODE_ASCII
bool "ASCII mode"
depends on FMB_COMM_MODE_ASCII_EN
endchoice
config MB_SLAVE_ADDR
int "Modbus slave address"
range 1 127
default 1
help
This is the Modbus slave address in the network.
It is used to organize Modbus network with several slaves connected into the same segment.
endmenu
code/09.extra/modbus/serial/mb_slave/main/idf_component.yml
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dependencies:
idf: ">=4.1"
espressif/esp-modbus:
version: "^1.0"
mb_example_common:
path: ${IDF_PATH}/examples/protocols/modbus/mb_example_common
code/09.extra/modbus/serial/mb_slave/main/slave.c
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code/09.extra/modbus/serial/mb_slave/sdkconfig.defaults
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#
# Modbus configuration
#
CONFIG_MB_COMM_MODE_ASCII=y
CONFIG_MB_SLAVE_ADDR=1
CONFIG_MB_UART_BAUD_RATE=115200
CONFIG_FMB_TIMER_PORT_ENABLED=y
CONFIG_FMB_TIMER_USE_ISR_DISPATCH_METHOD=y