https://forge.codesys.com/forge/talk/Runtime/thread/23ecb0f7d7/2020-02-27T17:31:55.980000ZRecent posts to Raspberry Modbus TCP master issue2020-02-27T17:31:55.980000Z2020-02-27T17:31:55.980000ZFlorentMhttps://forge.codesys.com/u/florentm/https://forge.codesys.comec0980ca53551725dabfdc2726482b71d41b348d

<div class="markdown_content"><p>Hi, </p> <p>I try to connect a Raspberry PI3 as Modbus TCP master with an arduino slave (ESP8266).</p> <p>But I'm facing some trouble.</p> <p>Slave side seems to be correctly configured because it is working fine with Modbus Doctor (Windows Software simulating Modbus Master).</p> <p>Can someone tell me what's going wrong with my setup?</p> <p>You will find WireShark captures, codesys project and printscreens.</p> <p>Thanks for your help.</p> <p>EDIT : </p> <p>OK I find that I need to read the variable in a POU to make the modbus values refreshing.</p> <p>But when I look at the Wireshark capture, the transaction ID is increasing each time the master requests a register.</p> <p>Why is this happen with codesys and not happen with Modbus Doctor?</p> <p><a class="" href="https://forum.codesys.com//download/file.php?id=3484" rel="nofollow">CodesysRaspberryModbusTCPMaster1.zip <span><span>[390.19 KiB]</span></span></a></p></div>