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Questions tagged [modbus-tcp]

A messaging structure developed by Modicon. It is used to establish master-slave/client-server communication between intelligent devices.

A messaging structure developed by Modicon in 1979. It is used to establish master-slave/client-server communication between intelligent devices. (from http://www.modbus.org/faq.php)

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How do I check connection status of Modbus-TCP?

I've set up a Modbus-tcp slave using NModbus4 library. I want to show the slave's status, whether it's listening(running?) or not running(idle?) - to show visually with green/red indicators. I've looked through NModbus4 library and couldn't find any…
Hyun Joon Jang
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pyModbusTCP PC to PC connection

I'm trying to connect two pcs together using pyModbusTCP. When I run both the client and server locally using local host it works just fine. When I try and run them on separate PC's the client takes a while to "connect" and then just reads the…
joshuagws
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Simple syntax to asynchronously get access to MODBUS register

I am trying to run three simple tasks in parallel using asyncio and sharing global variables. Two of them are working perfectly. One read websockets ("async with websockets.connect("ws://192.168.1.137:9000") as websocket:" Another one access IO via…
orion67
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PHP Modbus/TCP Address can only be up to 126

m use php to connect modbus\tcp by phpmodbus。 https://github.com/krakorj/phpmodbus/blob/master/Phpmodbus/ModbusMaster.php but address only up to 126 my Address is 32969 to 34597 equire_once dirname(__FILE__) . '/../Phpmodbus/ModbusMaster.php'; $IP…
jacklee
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EasyModBus modbusClient.ReadHoldingRegisters() returning unexpected 0

Background: We have been using the Schneider M251 PLC with the TM3AI8, TM3DQ8R and TM3DI8 modules for some time now and I have noticed that we are getting unexpected values being sent over Modbus tcp. Most of the time, the signal we receive over the…
Thornack
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Modbus Pulse Coils with Spring Boot project

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 from the specification: And more about Response and…
catch23
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How to Pass data from Broadcast Receiver to Recycler view Item

I am new to Android, I added Modbus client library to receive data from modbus device its successfully working in foreground, Using broadcast receiver sent to UI, Pass the data to recyclerview item below image (Change data…
Harish
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Modscan64 gives Timeout Errors for all responses

I am using Modscan64 to poll a service using TCP. I always receive this message: ** MODBUS Message TIME-OUT ** I connect to loopback 127.0.0.1. I have tried with function 3 (holding register) and function 4 (input register), using length 2 and…
Paul Chernoch
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Reading coil and holding registers concurrently using pymodbus3

I have a working code that can reads the coil status continuously using pymodbus3 library. The code is something like below. This is adapted from a basic sample and serves the purpose of looking for the coil status(address 0x01) change to "1" and…
Arun
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Newbie in Python and pymodbusTCP

I'm rather new with python and Modbus. Can someone provide me with some answer so that I do understand things a bit more. At our company we have a number of systems that have the possibility to provide data via ModbusTCP. As a hobby I would like to…
Robert
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How to read Modubus TCP/IP data with Apache NiFi?

I am having the data in Modbus TCP/IP. I have to read the available data with Apache NiFi. I don't know, which processor have to use exactly (Ex. GetTCP, ListenTCP, Plc4xSourceProcessor). Can you help me on this? Is there any feasibility with Apache…
Sathishkumar C
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Read SDM120 kwh meter with modbus over tcp/ip

I want to read the registers of an SDM120 kwh meter with modbus over tcp/ip. I have one Windows program Simply Modbus that works. The byte string that is send to the meter is "00 01 00 00 00 06 01 04 00 00 00 01". And I get results from register…
user3511320
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is C++ abstraction Endian neutral?

Suppose I have a client and a server that communicate 16 bits numbers with each other via some network protocols, say for example ModbusTCP, but the protocol is not relevant here. Now I know, that the endian of the client is little (my PC) and the…
Federico Spinelli
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Set but no Reset of Modbus Coils with ajax

I'm using ajax to create a modbus connection an write coils. My Problem is that i can set coils as true but not false.. Side to call from Browser: Startseite …
Marcel Koch
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libmodbus - monitor and restart connection

I am developing a Modbus TCP client on Linux to communicate with different Modbus devices using libmodbus. To initialize the TCP connection, the function int modbus_connect(modbus_t *ctx); is called and returns 0 if the connection was successful. I…
Engineer999
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