Questions tagged [modbus]

Modbus is a simple protocol for serial communication between electronic devices.

Filter by
Sorted by
Tagged with
9
votes
4answers
7k views

How to interconnect multiple Arduinos with a Rpi to control home-lights/switches

While planning the lightning infrastructure (wall-switches and lights) of my new home (it's still under-construction) I choosed to go through the "automated route" way and due to my background (I'm an ...
5
votes
1answer
2k views

Modbus Communication protocol for Arduino as Slave

I have an Arduino Uno board, with these components: rs-485 Modbus module shield Multiprotocol radio shield board for Arduino In addition I have a level sensor which reads either 1 when it is above ...
3
votes
1answer
20k views

Modbus RTU controller monitoring with arduino and RS485 module

I'm a medium user in Arduino. I baught a pHmeter controller with RS485 output (MODBUS RTU protocol). I want to get pH value read by the controller over RS485 module and Arduino. According the ...
3
votes
1answer
1k views

Arduino throwing error while using modbus RS485 code

I have been trying to make a communication with my industrial drive. All I want to do is read a few values of drive, like current, voltage etc. For that I am using a library: I don't understand why ...
3
votes
1answer
2k views

Response of Modbus Protocol

I have the below code. This code is successfully compiling and uploading, but I am not getting any response from Slave. What do I need to do? Some time data being received from Slave (I get this ...
3
votes
0answers
310 views

Modbus TCP/IP using Arduino uno and ENC28J60 module

I have this project where I need a modbus tcp server that will host a series of sensor data for other modbus client devices to read. I use this Library by Andresoarmento This is the code i am using ...
2
votes
2answers
22k views

Arduino ModBus RTU master communication with Power Meter problem

i have an arduino UNO with RS485 module. I have made this connection: And i have an problem with communication of this module with power meter "InePro PRO-1Mod" (datasheet) over ModBus protocol. I ...
2
votes
1answer
170 views

Connect 12v DC sensor to Arduino UNO using TTL RS485

I'm trying to connect Arduino Uno with BGT PM2510 sensor (which uses 7-12V DC) by using UART TTL to RS485 Two-way Converter. The only thing I wonder is can the sensor damage the MCU ? According to the ...
2
votes
1answer
10k views

Is there any good working MODBUS TCP master library available for Arduino?

I would like to connect with Fronius solar inverter through MODBUS TCP with Arduino to READ and WRITE register values only. I want to set the Arduino as master and the Inverter as slave. I want to use ...
2
votes
1answer
687 views

Modbus master arduino code is throwing weird errors on upload

I am using the following https://code.google.com/p/simple-modbus/ arduino master library code. In order to communicate with my industrial drive. All seems right but I am getting some weird errors. I ...
2
votes
1answer
641 views

ModbusMaster.h - changing node

I'm using the ModbusMaster.h library on a project, with arduino-uno and a TTL/RS-485 converter, and the function has to identify the slave that it is communicating. The slaves goes from 1 to 16. After ...
2
votes
1answer
39 views

Which sensor bus best to use?

I am working on a project which requires a dozen VL53l0X I2C-TOF sensors to be polled by one master MCU over a few meters of cable. Thus, I decided to accompany each TOF by an Atmega8 acting as a ...
2
votes
1answer
819 views

Need Help to implement MODBUS TCP Master over Atmega32 MCU

I am doing a project where I have to interface with Fronius Solar Inverter with Atmega32 MCU over MODBUS TCP. I want to set the MCU as client and The inverter as Server and I have to implement two ...
2
votes
0answers
511 views

Arduino Modbus slave error

I am trying to use Arduino as Modbus- RTU slave and Raspberry Pi as a Modbus master I have interfaced Max485 (RS485 to TTL converter) with Arduino and Rs485 to USB converter in Raspberry Pi, Initially,...
2
votes
0answers
1k views

Modbus Protocol RTU

I have simple code working on Serial Communication asn below. With Same data i would impliment Modbus protocol> I have Used Modbus library for arduino earlier which works fine with 9600 baudrate and ...
2
votes
0answers
730 views

Negative value conversion for modbus slave

I have an analog sensor which reads values 0-5v, -75 degrees to 75 degrees. Now I have converted to +75 degrees and -75 degrees format depend on the voltage. From 2.5v to 5v data is read properly (i....
1
vote
1answer
7k views

How to make I2C work on RS485?

I'm trying to optimize the communication (minimize wires) on a project where I can control a motor and toggle some 230V devices by using RS485 and I2C. On this project, I'm using an Arduino (Mega) ...
1
vote
1answer
58 views

Simple ModBus Master function 15

I have a simple setup with arduino Nano as slave and a arduino Mega as master Can anyone explain how the function 15 FORCE_MULTIPLE_COILS Works i have been running some test on this and cant figure ...
1
vote
1answer
147 views

Arduino Modbus Slave Library Needed

We are building a circuit based on ATMega328* that : Reads 32 current transducers, multiplexed into one Analog Input, Reads 12 voltage transducers, multiplexed into one Analog Input, Reads 6 ...
1
vote
1answer
406 views

Cannot read modbus data repetitively

I try to communicate with 2 RS485 sensors (pH and EC), but I have some troubles with my code. First, I tried to get data from just one: The function in charge of request sending: String GET_probe(...
1
vote
1answer
371 views

Cannot obtain reading from meter (Modbus)

I have a system in which I am taking readings from a meter and processing it through an Arduino Nano. My code looks as follows: #include <SoftwareSerial.h> #define SerialControl 7 #define ...
1
vote
2answers
8k views

Modbus RTU slave library

I want to use an Arduino Genuino Zero as a Modbus slave. I tried to search on google, and found a library. When I try using the library, I get a timeout error. Can anyone tell me how to solve that ...
1
vote
1answer
768 views

Connect Arduino to PLC (Data Exchange)

The Arduino should read data from a PLC. Has anyone experience with this? What would be possible interfaces? I would prefer OPC-UA, but all the research I did, only OPC-DA was mentioned. Thanks in ...
1
vote
2answers
567 views

Communication arduino MODBUS fails on high number of registers

When I try to run the following program it runs ok: #include <modbus.h> #include <modbusDevice.h> #include <modbusRegBank.h> #include <modbusSlave.h> #include <...
1
vote
1answer
2k views

Modbus slave data into word

I have simple code. The library downloaded from github:smarmengol/Modbus-Master-Slave-for-Arduino. I wanted to store floating point. In the code blow, I type casted to integer value. As I know ...
1
vote
0answers
28 views

The Pfieffer Vacuum Protocol for RS485

i am working on a control Interface for serveral Components including turbo Pumps from the company Pfeiffer. The communication will be done according to the The Pfieffer Vacuum Protocol for RS485. ...
1
vote
0answers
82 views

ESP32-POE/ISO unstable after 10 days of power up

i have one ESP32-POE and ESP32-POE and i'm using the Olimex RS485 module to read a power meter that is placed near the ESP32 (5 meters of CAT5 cable - 9600 8N1). My device has this workflow (it's ...
1
vote
0answers
462 views

How can i read and write the data from a Delta plc-s series through Arduino UNO?

I am trying to communicate PLC with arduino through rs232 as well rs 485. But, I am not able to read and write data. I can observe the data in PLC through ladder logic but not in arduino. I am trying ...
1
vote
0answers
884 views

can ModbusRtu.h library send data from slave to master using modbus(RS485) module?

i am using ModbusRtu.h library for modbus protocol. it works for sending data from master to slave but it can not send data from slave to master. master code: #include <ModbusRtu.h> #define ...
1
vote
0answers
50 views

I am interfacing Amonia Sensor RS485 output with Arduino Mega . not getting any response

I am interfacing Amonia Sensor RS485 output with Arduino Mega but not getting any response. i need to transmit {0x06, 0x03, 0x00, 0x00, 0x00, 0x04, 0x45, 0xBE}; frame to sensor then senor will send ...
1
vote
0answers
267 views

Reading a simple sensor with Modbus RTU on Arduino Uno

I'm integrating a wind direction- and speed sensor with an Arduino. It communicates over RS485 Modbus RTU, which I don't have any experience with. The documentation is very short, and it just says: ...
1
vote
1answer
1k views

NodeMCU Modbus interfacing with Pressure Multi-Switch

I've been trying to interface between a NodeMCU and a Dotech DPX200 Pressure Multi-Switch over Modbus RS485 using a MAX485 Module for the past few weeks, going through nearly every Modbus post on this ...
1
vote
0answers
306 views

Arduino Mega with SIM800L running Modbus TCP/IP

I'm trying to set up an Arduino Mega with a SIM800L module and trying to get Modbus TCP running on said Mega. I've set Modbus TCP over wifi and serial before but I used libraries for those. The ...
1
vote
0answers
523 views

Unable to read data more than once via Modbus RTU

I'm a newbie to this forum so kindly excuse me for any errors. I'm using an Arduino Uno and Max485 (RS-485 to TTL) to communicate with a Power meter, but I'm able to receive the data from the Power ...
1
vote
0answers
251 views

RS485 Arduino Communication Issue

Friends, I am trying to achieve half duplex communication between two Arduinos using RS485 Protocol. The hardware I am using is a MAX485 module and an Arduino Uno. I am using the SoftwareSerial ...
1
vote
0answers
121 views

Arduino as Modbus RS485 slave using only 2 Digital pins

I want to use RX(0) and TX(1) Pins to make Arduino as an RS485 slave. To do this I am using MAX485 IC (Breakout board) https://datasheets.maximintegrated.com/en/ds/MAX1487-MAX491.pdf The problem here ...
1
vote
0answers
1k views

Arduino Modbus - Rtu slave with Raspberry pi using MAX-485

I am trying to use Arduino as Modbus- RTU slave and Raspberry Pi as a Modbus master I have interfaced Max485 (RS485 to TTL converter) with Arduino and Rs485 to USB converter in Raspberry Pi, Initially,...
1
vote
0answers
242 views

Anyone using ModBus RTU on Galileo gen 2?

I'm trying to communicate with some industrial hardware, on ModBusRTU, from my Intel Galileo Gen2 board. I use this board to convert UART to RS485 http://linksprite.com/wiki/index.php5?title=...
1
vote
0answers
1k views

MODbus response for configure data

I am not able to receive data. I am able to send data from master but am not getting any response. This program uploaded successfully. I have below setup to monitor data from Modbus. I have included ...
0
votes
2answers
2k views

Arduino Uno & ESP32 communication using RS485

I am trying to establish a communication between Arduino Uno ( Master) and ESP32 (Slave) using RS485 protocol (using MAX485 module). I have successfully done this between two Arduino Unos. ...
0
votes
2answers
757 views

float not a float

I am trying to read a SDM220 meter on my solar setup. I've been reading it using Modbus SCADA, so know it all works ok. But I want to read it with my Arduino Mega 256. My problem is that when I run ...
0
votes
1answer
1k views

Why ModBus RTU Master-Slave Dont Work

I have two mega arduino and want to them communicate with modbus rtu together, i use below link circuit for this : http://www.microcontroller-project.com/rs485-communication-between-arduino-mega-and-...
0
votes
1answer
82 views

Controllino Mega and Fatek HMI

I have a setup that controls the rotation of two stepper motor using Arduino UNO, HBS860H stepper drivers, 4X4 keypad and LCD screen. I have replaced the Arduino Uno by a Controllino Mega and it works ...
0
votes
1answer
810 views

Controlling VFD with ModBus RTU via RS485 and Arduino

I am attempting to control a Folinn VFD (Manual: Manual) with an Arduino Uno via a MAX485 module such as this. Pins for MAX485: DI > D8 DE & RE > D10 RO > D11 VFD settings: F00.01 set to 2 ...
0
votes
1answer
1k views

Stack smashing protect failure ESP32 with Modbus RTU

I'm doing a project using an ESP32 TTGO with LoRa, the Max485 and a WELLPRO ADAM 8082 for Modbus communication. I'm trying to use the ESP32 as a master to and the ADAM as a slave. I'm also using Node-...
0
votes
1answer
2k views

CRC16 calculation for MODBUS RTU [closed]

I am trying to communicate an industrial type counter using Modbus. I have to calculate CRC16 value as two byte for send it. I previously googled for few Arduino libraries and I get a same function as ...
0
votes
2answers
959 views

Problem with modbus communication between two arduinos when writing more than 27 registers

I have the following problem: I want send 200 registers from a modbus master to a slave. Both are arduinos. I can't send more than 27 registers. When I send more i get the Errorcode 255 which means ...
0
votes
1answer
1k views

Using Modbus-RTU with Arduino and temperature controller

I'm trying to connect with a 4 channel temperature controller using Arduino Modbus Library. This is a part of my temperature controller datasheet. It has register for read PV of each channel. I have ...
0
votes
1answer
2k views

Using Modbus TCP server on Arduino

I have a scd30 sensor wired to an Arduino Uno. The scd30 works on the I2C protocol. I am able to read data live on the serial monitor on the Arduino IDE. I have an ethernet shield on my Arduino. I ...
0
votes
2answers
132 views

How to control two devices with Arduino? [closed]

I want to control two devices: AC Humidifier I have a DHT11 sensor for temperature and humidity. I want the AC to turn on when the temperature is greater than 30°C, and off when it's less than 20°C....