https://forge.codesys.com/forge/talk/Runtime/thread/4a8876e18e/2022-05-18T11:47:44.454000ZRecent posts to Wago 750-8204 vs Wago 750-8214 Modbus RTU Master2022-05-18T11:47:44.454000Z2022-05-18T11:47:44.454000Zsomlioyhttps://forge.codesys.com/u/somlioy/https://forge.codesys.com3a75bb687e8393070b9adb09dee74726e8662c70

<div class="markdown_content"><p>Shouldnt be any difference ...<br/> Are they running the same FW aswell?</p> <p>I'd expect it to be an configuration issue since the Port can behave as RS232, 422 or 485.<br/> Also verify that there is no owner assigned to the serial port on WBM.</p></div>

2022-04-20T11:17:06.739000Z2022-04-20T11:17:06.739000Zhappychappyhttps://forge.codesys.com/u/happychappy/https://forge.codesys.com62c4ac25c5203103e4af30d9704b47acdba3dc91

<div class="markdown_content"><p>Second Image:<br/> Modbus Slave Not Running and Timeout</p></div>

2022-04-20T11:16:34.443000Z2022-04-20T11:16:34.443000Zhappychappyhttps://forge.codesys.com/u/happychappy/https://forge.codesys.com105d92532f845ef4de9e15a062bc017a7d738c46

<div class="markdown_content"><p>First Image:<br/> Modbus Port Open and Running</p></div>

2022-04-20T11:15:16.367000Z2022-04-20T11:15:16.367000Zhappychappyhttps://forge.codesys.com/u/happychappy/https://forge.codesys.comfd6d52f484449d6cfe0f3ccee7f01e32f3f4ab2a

<div class="markdown_content"><p>Hi</p> <p>I am using Codesys V3.5 SP17 (64Bit) and I am experiencing the following issue:</p> <p>I download my program to a 750-8204 CPU (Modbus Master) that communicates to a Slave Modbus PSU. When I select the modbus master, it shows the Bus is running but when I select the modbus slave device, it shows timeout, and I can see the counter incrementing for requests that is being sent out.</p> <p>However when I connected RS485 to USB as a slave on the Modbus network I do not see the Master transmitting any data.</p> <p>When I download that exact program to a 750-8214 CPU, immediately the RS485-USB converter detects activity on the Modbus network and I could see the slave devices reacting.</p> <p>Is there something on the hardware side of the PLC of the older Wago models that requires more software setup to work?</p> <p>See attached pictures of the results when the program is on 750-8204</p></div>