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Questions tagged [pymodbus]

Pymodbus is a python implementation of modbus protocol providing both client and slave features.

PYMODBUS is a full modbus implementation of modbus protocol using python. It provides both client and server features and supports Modbus over RTU, ASCII, TCP, UDP protocols. The library also supports both synchronous and asynchronous variants of both client and server features.

Pymodbus is supported on both on python 2.7 and python 3.x

For more info refer

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decode register to 32bit float big endian in python code on raspberry pi 3B with python library pymodbus2.5.3

I'm trying to get the data stream of a sensor transmitter that uses the modbus rtu communication protocol on my raspberry pi 3B. I'm able to get the data with the pymodbus2.5.3 library. For this I use this code: from pymodbus.client.sync import…
olefine921
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Pymodbus read and decode register value

I am new to modbus comunication, i have to read from an inverter a single value from one register using modbus protocol (i use python with pymodbus for this): From the inverter documentation i read about register documentation: Register ADR:…
Manuel Santi
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How to use AsyncModbusTCPClient from pymodbus.client.asynchronous.tcp in a coroutine?

Based on the 'Async Asyncio Client Example' of PyModbus I tried to initialise the client in a coroutine. The example in run_with_already_running_loop() is working fine but initialising ModbusClient hangs without timeout or error message when run in…
Gerard
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Modbus Python Schneider PM5300

I'm trying to get voltage or current from PM5300 meter, but always come 32768 only. The code: from pymodbus.constants import Endian from pymodbus.payload import BinaryPayloadDecoder from pymodbus.client.sync import ModbusSerialClient as…
Vinícius
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pymodbus Modbus Server implementation with multiple slave devices context - writing to a register overwrites to all slaves

I have an issue with a simple pymodbus server implementation. From what I have read in the docs, this implementation should have unique slave contexts for each slave device, i.e. writing to device 0x01, register address 1, should be a different…
Crashtastic
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Can I write in an Input Register? Modbus

I've been working for 2 months in a MODBUS project and now I found a problem. My client is asking me to write in an input register (Address 30001 to 40000). I thought that was not a thing for me because every modbus documentation says that 30001 to …
Rauññ
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Unpack IEEE 754 Floating Point Number

I am reading two 16 bit registers from a tcp client using the pymodbus module. The two registers make up a 32 bit IEEE 754 encoded floating point number. Currently I have the 32 bit binary value of the registers shown in the code below.…
WK123
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Is it possible to simulate a rs485 slave using pymodbus?

I've been using node-red to simulate TCP and RTU slaves on a raspberry pi and a dell gateway. So far, I've managed to get the TCP slave working, but it doesn't seem possible to do it via rs485 on node-red. Is it possible to use pymodbus running on a…
MattieG4
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Convert two raw values to 32-bit IEEE floating point number

I am attempting to decode some data from a Shark 100 Power Meter via TCP modbus. I have successfully pulled down the registers that I need, and am left with two raw values from the registers like so: [17138, 59381] From the manual, I know that I…
Andrew Sclafani
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Cannot read more than 13 registers at once

This is my code: from pymodbus.client.sync import ModbusSerialClient as ModbusClient client = ModbusClient(method='rtu', port='COM7', timeout=1,parity='N', baudrate=9600, unit=1) status = client.connect() print(status) rr =…
Hari
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modbus error failing to connect to ModbusTcpClient when reading/writing

Recently I have been tasked with a project involving reading Modbus data, specifically with the pymodbus package. before diving into this project I wanted to simulate some reading and writing of Modbus data (without having to use a machine) with…
Fastas
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How to update the value of pymodbus tcp server according to the message subscribed by zmq？

I am a newbie. My current project is when the current end decides to start the modbus service, I will create a process for the modbus service. Then the value is obtained in the parent process, through the ZeroMQ PUB/SUB to pass the value, I now want…
fish
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"client.read_holding_registers" Problem RTU pymodbus

i am trying to read temperature values from a PLC using pymodbus but it's not working. This is my code: from pymodbus.client.sync import ModbusSerialClient as ModbusClient import logging logging.basicConfig() log =…
Pedro Melo
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Cannot import BinaryPayloadBuilder from pymodbus

I tried to write this code below: from pymodbus.payload import BinaryPayloadBuilder But raises an error: ImportError: cannot import name 'BinaryPayloadBuilder' from 'pymodbus.payload' Need your help please.
Omar Ghorbel
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Why introduce zero_mode and why default is False?

I don't know why pymodbus need zero_mode arguments? Any use case? Seems usually we want to get what we set. ModbusSequentialDataBlock(0, [1, 2, 3, 4])) # And we expect get [1, 2, 3, 4] when client.read_holding_registers(0, 4) - # The slave…
foxiris
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