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Questions tagged [modbus]

Modbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers (PLCs). Simple and robust, it has since become a de facto standard communication protocol, and it is now amongst the most commonly available means of connecting industrial electronic devices.

Modbus is a serial communications protocol published by Modicon in 1979 for use with its programmable logic controllers (PLCs). Simple and robust, it has since become a de facto standard communication protocol, and it is now amongst the most commonly available means of connecting industrial electronic devices.

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Python modbus library

I have to control a modbus device with a serial interface. I've got not experience with modbus. But my short research revealed several modbus libraries pymodbus MinimalModbus Modbus-tk uModbus What are the advantages/disadvantages, are there even…
P3trus
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Hosting multiple clients with freemodbus

I am working on a project involving a microcontroller communicating to a PC via Modbus over TCP. My platform is an STM32F4 chip, programming in C with no RTOS. I looked around and found LwIP and Freemodbus and have had pretty good success getting…
JNMarch
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Is there a good library for dealing with the Modbus protocol in .NET?

Does anyone know of a good (preferably open source) library for dealing with the Modbus protocol? I have seen a few libraries, but I am looking for some people's personal experiences, not just the top ten Google hits. I figure there has to be at…
GEOCHET
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Calculating Modbus RTU CRC 16

I'm implementing a software where I read and write data in Modbus RTU protocolo via serial. For that, I need to calculate the two CRC byte at the end of the string of bytes, but I'm being incapable of doing this. Searching throughout the web, I…
Momergil
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Modbus Error: [Invalid Message] Incomplete message received, expected at least 2 bytes (0 received)

Problem pymodbus master/client can send a request to the slave/server. The slave/server make the things to return ready and is waiting for the master/client to pick them up. Despite the readiness of the server/slave, the master/client just returns…
Andreas
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ARM: reading modbus data through UART fails

I am trying to read a register from an RS485 adapter using a UART connection on an ARM board with no success Machines ARM board: CM-T335 - TI AM335x Computer-on-Module http://www.compulab.co.il/products/computer-on-modules/cm-t335/ PC: x86 machine…
Taher
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Calculating modbus RTU 3.5 character time

am new to Modbus and developing an application using Modbus RTU. I would like to know how to find out the RTU message frame separation time. In the Modbus RTU specification, It mentions 3.5 chars time, but there is no more data about how i can…
user3128453
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Getting the CRC checksum of a byte array and adding it to that byte array

I have this byte array: static byte[] buf = new byte[] { (byte) 0x01, (byte) 0x04, (byte)0x00, (byte)0x01,(byte)0x00, (byte) 0x01}; Now, the CRC checksum of this byte array is supposed to be 0x60, 0x0A. I want the Java code to recreate this…
GreenGodot
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Need modbus Java library

I need simple modbus Java library with source code. I found on google but there is .jar file and doesn't have strong using manual. Can anybody suggest me modbus library with using manual or source code ?
Damir
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Create a simple Client/Server using Modbus in C

I am currently working on a project which will allow different automates to communicate. To do so, I would like to create a client and a server that will talk using the modbus protocol. I am not sure if I want to be using ModBus/TCP, ModBus/RTU or…
PiggyGenius
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Reading registers with pymodbus

I am very new to Modbus and PyModBus however I have spent a good amount of time trying to read up and experiment with it. If anyone could point me in the right direction I would appreciate it... I have a drive with distance, velocity,…
5T4TiC
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Modbus stack for Microchip PIC

Can someone suggest an open source implementation of a Modbus RTU Slave for a Microchip PIC18 processor? I'm looking for an implementation of Modbus RTU for RS-232/RS-485, but a Modbus TCP/IP implementation would be welcome as well.
mjh2007
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Function to calculate CRC16 (Modbus) value

Using C#.net,WPF application.I'm going to connect to a device (MODBUS protocol), I have to calculate CRC (CRC16). Function which i use calculate normal crc16 and value is correct,but i want the value for CRC16(modbus) one. Help me to sort out.
user2720620
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Modbus Communication

I am using C# to communicate via modbus rs485 rs232 to 2 phase meters that among other log the power voltage. I have to send data over the bus so that i can receive the readings. I have connected a normal wire and shorted the send and receive. The…
Combinu
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Multithreading and Serial Ports

Ok..this will be lengthy but I need to explain some background first. This part of my software is for sorting items running down a conveyor belt. I am using Modbus for the conveyor belt. Modbus will open gates at a specific time to let an item go…
CSharpDev
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