I have modbus mapping setup in my AB Micro820 PLC. I have an array in 40001 for writing, and one in 42001 for reading. Both are 200 elements and REAL type (32-bit float). I can write and read curre...

how can I read from Register with pymodbus? I'm trying this piece of code: import pymodbus from pymodbus.pdu import ModbusRequest from pymodbus.client.sync import ModbusSerialClient as ModbusCli...

I' trying to connect from my Mac laptop to a Modbus device (MR-SI4) using a serial connection using a USB RS485 converter that gets "mounted" to /dev/cu.SLAB_USBtoUART. This is my code: import lo...

I have to control a modbus device with a serial interface. I have no experience with modbus, but my short research revealed several modbus libraries pymodbus MinimalModbus Modbus-tk uModbus ...

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 val...

I've been reading about these two protocols lately and wasn't quite able to understand why to use MQTT when we have MODBUS (or vice versa). Since, MODBUS is used to transmit data over serial commu...

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 Fr...

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 s...

Have to implement call to Digital IO with Modbus protocol on Spring Boot project build by Maven. It should be a pulsed call with some duration at the body (like 5 seconds, etc.) Here is a snippet f...

In modbus there are 4 object types which are Input registers (R), Holding registers (R/W), Input Bits (R) and Coil Bits (R/W). What's stopping someone just using holding registers? Why are the othe...

I have 2 types of devices that have different protocols and are connected with a single serial port. By protocol, I mean that serial port configurations are different. I have a protocol id p_id by ...

I have a device that uses Modbus TCP. I want to read data from it and display it on a webpage (Without an in between server). I have found a project that does almost this exact same thing as a Chr...

I'm writing a small program using QModbusDevice over the serial port (using the QModbusRtuSerialMaster class) and have some problems. One of the problems seems to be that the flow control of the s...

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 ...

I have one energy meter and i am trying to retrieve voltage, freq values from meter on raspberry pi uart over RS485 My connections for raspberry pi and rs485 are as follows Rs485 DI - Tx of raspb...

I am using the ModBus RTU, and I'm trying to figure out how to calculate the CRC16. I don't need a code example. I am simply curious about the mechanism. I have learned that a basic CRC is a polyno...

Can anyone explain how to create the request and get the response in right way using pymodbus via Modbus TCP/IP? I have the PLC which I want to use as slave and PC - as master. I trying to do it in...

I need to work with Modbus RTU on C++. I have been trying to follow the instructions on https://github.com/stephane/libmodbus but I couldn't really get the hang of it. Could someone who knows how t...

I'm attempting to get an RS485 adapter connected at the UART to communicate via modbus on a Raspberry Pi. My end goal is to have all this working with a Node application, but so far my dev has been...

I have some modbus TCP code written under pymodbus 1.2 the relevent code was result = modbus_client.read_holding_registers(40093, 3) After updating to pymodbus 1.4.0 it wouldn't work until I carg...

I am having a lot of trouble on generating a modbus CRC16 code using PHP. I have found a lot of different codes over the internet but i have tried them and for some reason i didnt get right results...

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 t...

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/...

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...

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 0x6...