Raspberry Pi Stack Exchange
Raspberry Pi Stack Exchange

Questions tagged [modbus]

34 questions
7
votes
5 answers

pymodbus rtu RS-485 communication

I have this little device for communication, and I can see the dongle after lsusb, and it is attached to ttyUSB0 (output from dmesg). Since the module has its driver that is installed to Raspberry Pi, I don't need another CPU for handshake. I am…
Cugomastik
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1 answer

Serial USB-RS485 failing to read on Pi but not on Ubuntu laptop?

I am reading values from a Battery Management System using two, serial USB-RS485 adaptors (ftdi). I am doing this over MODBUS using the minimal modbus library and python: # Bank A # port name, slave address (in decimal) instrument_A =…
Peter Turner
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0 answers

Modbus on Raspberry Pi

I am quite new to Raspberry Pi and Modbus. I am going to implement a Modbus RTU on Raspberry Pi using libmodbus. I followed this totorial as a simple Modbus test, but when I compile the bandwidth-server-one and run the code, nothing happens and look…
dorsa
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2 answers

RS-485 and Raspberry Pi

How does RS-485 communication between Raspberry Pi and various sensors work? Note: I would like to use it with Pyhton 2.7. Can I connect ADM485 to the UART (Tx, Rx) of Raspberry Pi? I want to use minimalmodbus to communicate with Arduinos receiving…
Ruthvik Vaila
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2
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1 answer

For communicating with a modbus rtu slave using rs485 to usb converter, does Raspberry Pi require any configuration?

I have a modbus slave device and a rs485 to usb converter. I used the converter and successfully read data from the slave device with my laptop but when I try to use it with the Raspberry Pi I am unable to do so. I am using ssh and vnc to remote…
Shounak Katyayan
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2
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1 answer

Raspberry pi pico modbusRTU communication as master with slave computer using micropython

I am working on a slave computer and want to save the data transmitted from the master raspberry pi pico. In micropython there is modbus library github link. I want to use this library but there is a hardware issue about using rs485. I want…
noobinmath
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1 answer

Modbus rtu on pi

Would anyone have any recommendations for a modbus newbie on getting a pi to talk to a communicating sensor? 2 options Option 1, $10: https://www.amazon.com/Serial-Converter-Adapter-interface-FT232RL/dp/B01MYSQLF0 And these…
bbartling
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1
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0 answers

Trying to use pymodbus as a slave but getting error

I have been successful using modbus-tk with an off the shelf modbus master simulator. However, when the real master is wired in (an Automation Direct PLC), the master does not get any response from the slave. So I'm looking at using another modbus…
mspath
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1 answer

Modbus communication

I try to read data from a device by raspberry 3 B+. those two devices are connected via CH340G usb module (USB to Serial (TTL) adapter). Concerning the python code; here's: from pymodbus.client.sync import ModbusSerialClient as ModbusClient …
Brahim
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1
vote
1 answer

Multithreading Python Raspberry Pi 3 B+

My Raspberry Pi 3 b+ is reading by Modbus the values of an irradiation sensor, processing all the data, showing it in a plot and showing some warnings (if the irradiation ramp is higher than 5%). I am computing all this in a Python process but it…
Dani
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Connect multiple sensors on a single USB to RS485 adapter

On tindie I bought a RS485 soil moisture sensor with a USB to RS485 dongle. I want to add more sensors for monotorring multiple plants. Since RS485 is a bus system, it seems basically possible to connect multiple sensor on the same USB dongle. The…
Lion
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1 answer

How do I program a Raspberry Pi obtain information from PLC's registers using Modbus TCP/ICP?

I am trying to extract data from programmable logic controller's registers using Raspberry PI module and then display it on screen. I have installed pymodbus package on my Rpi. I am quite unsure how to proceed further.
Sahan
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ModBus RS485 adapter for GPIO

I have just purchased my first Raspberry Pi 2B. We plan on using it to develop a standalone application with a very high reliability requirement (isolated locations). Is it possible to connect it to the GPIO header, or is a usb converter the only…
klonq
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2 answers

Error in reading data with pymodbus

I have been trying to read data from a modbus slave device using pymodbus. After much research I found this code on internet. It is a straight forward code. I am able to read the data on windows but RPi returns "none". There have been similar…
Shounak Katyayan
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1
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0 answers

Is there a modbus rtu tester for Raspberry PI?

I need a tester much like modpoll but one that runs on Raspbian OS. I need to check if my Raspberry Pi is able to communicate with my modbus slaves.
Shounak Katyayan
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