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Problem with modbus tcpip

Hi, I'm building an automation in which I use the Siemens IOT 2020, this must communicate with devices using the ModbusTCPIP protocol.

I managed to make the network work using the libraries made available to the Arduino IDE.

I can not get the Modbus to work

in qando I do the test using modscan 32 mi from the time out error.

I tried to use those found on the net but they do not work.


The code I try is this:


#include <Mudbus.h>


#include <Ethernet.h>

// the sensor communicates using SPI, so include the library:

#include <SPI.h>



// assign to MAC address for the ethernet controller.

// fill in your address here:

byte mac [] = {

  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};

// assign an IP address for the controller:

IPAddress ip (192.168,200,210);

IPAddress gateway (192.168,200,254);

IPAddress subnet (255, 255, 255, 0);



// Initialize the Ethernet server library

// with the IP address and you want to use

// (port 80 is default for HTTP):

EthernetServer server (5002);



Mudbus Mb;


void setup () {

  // start the SPI library:

  SPI.begin ();


  // start the Ethernet connection and the server:

  Ethernet.begin (mac, ip);

 server.begin ();



  Serial.begin (9600);

Mb.R [0] = 10;

  Mb.R [1] = 100;

  Mb.R [2] = 20;

  Mb.R [3] = 30;



  delay (1000);






void loop () {

  // check for a reading no more than once a second


Mb.Run ();


  // Analog inputs 0-1023

  Mb.R [0] = analogRead (A0); // pin A0 to Mb.R [0]

  Mb.R [1] = analogRead (A1);

  Mb.R [2] = analogRead (A2);

  Mb.R [3] = analogRead (A3);

  Mb.R [4] = analogRead (A4);

  Mb.R [5] = analogRead (A5);







Thank you and greetings

0 Votes


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[Comment was deleted]

September 18, 2018 10:26

I have not used the Arduino Sketch Modbus library you mentioned, in my testing I used a Modbus Module within Node-Red, I found this far more useful and you get all the benefits of Node-Red as well. Is there a reason you need to use it within an Arduino Sketch ?

0 Votes

[Comment was deleted]

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