Questions tagged [modbus]

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

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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 ...
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0answers
507 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,...
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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 ...
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0answers
728 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....
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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. ...
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0answers
81 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 ...
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0answers
453 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 ...
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871 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 ...
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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 ...
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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: ...
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305 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 ...
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521 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 ...
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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 ...
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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 ...
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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
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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=...
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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 ...
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1answer
46 views

Modbus TCP together with MQTT over same ethernet

I'm currently in a planning phase for a project. I want to read some sensor data over Modbus TCP, do some simple calculations on the Arduino and publish the results over MQTT. Which means I have 2 RJ-...
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78 views

Modbus RTU MAX485 AFD Yaskawa V1000

I need some help with my proyect. I want send some data to an AFD Yaskawa V1000. I have the bytes test and I send it but I cant comunicate with it. The AFD just show an 'CALL' error, means dont have ...
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0answers
89 views

ModbusMaster - Read 64 Bit integer

i'm using ModbusMaster library (Repo) to read from a device some registers. Many of them are float and i've no problem to read them using the following code: //for float conversation union { ...
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1answer
557 views

read data from controller via RS485 Modbus rtu Arduino

I have a device with an rs485 port from which I would like to read the ph value. Below is the connection with the RS485 adapter. I tried to read the data with this code but doesn't work: #include ...
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0answers
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Modbus programming

I have a Controllino Mega running a code that rotates a stepper one revolution CW, and one revoluction CCW. I need the program to run, just when a signal is received from an HMI that I have connected ...
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0answers
84 views

how to link arduino uno and wonderware via modbus?

I am trying to make my Arduino uno and gy-521 accelerometer a modbus tcp server to feed data to a client on my pc. Most likely the HMI I am going to be using is wonder ware. #include <Wire.h> ...
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1answer
451 views

How to Use Function Code 6 Modbus RTU library

I'm trying to communicate with a temperature controller using Modbus RTU. I used this Arduino library. I was able to read PV(current temperature value) using below code. It uses Function code 4. I ...
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1answer
936 views

Multiple #ifndef vs. single one #endif

My question is connected with the issue as linked: Is there any good working MODBUS TCP master library available for Arduino? An example of Modbus TCP master library as suggested in the post above. A ...