https://forge.codesys.com/forge/talk/Engineering/thread/37d49fd1e7/2021-08-27T05:05:09.385000ZRecent posts to Modbus TCP Slave Unit Id2021-08-27T05:05:09.385000Z2021-08-27T05:05:09.385000Zi-campbellhttps://forge.codesys.com/u/i-campbell/https://forge.codesys.comec7850957f6f6914bc3fde8581fe78d52336e061

<div class="markdown_content"><p>The Modbus TCP Spec at modbus.org says 0xFF should be used to address the device, and other addresses are for gateway architectures.<br/> I will see if there is a workaround.</p></div>

2021-08-27T05:00:09.964000Z2021-08-27T05:00:09.964000Zi-campbellhttps://forge.codesys.com/u/i-campbell/https://forge.codesys.com2ebc2eb2977340c65763896475918816e77f82b0

<div class="markdown_content"><p>right click the modbus tcp slave, add device, add a "modbus slave, com port". here you can set the unit id.</p> <p>You could suggest an improvement to the PLC Manufacturer, that they use 0xFF as a slave ID, when the PLC is not acting as a modbus gateway. You could link them to the Modbus TCP spec at modbus.org where it explains this. That is, unless there is a TCP-Serial gateway in your architecture.</p></div>

2021-08-27T04:24:11.697000Z2021-08-27T04:24:11.697000Zashwinsekarhttps://forge.codesys.com/u/ashwinsekar/https://forge.codesys.comc37d74be82ac19b563c3395c91afedc7350ac815

<div class="markdown_content"><p>Hi,<br/> I am trying to setup a modbus tcp communication between <strong>Control Win x64</strong>(Server) and a PLC(Client),<br/> The slave id of the PLC can be set only between 1 -247,</p> <p>I am able to read values using modscan from Control Win x64 setting the device ID to 255,</p> <p>Is it possible to change the Slave id of the modbus server any value between 1 to 247?</p> <p>I am using Codesys 3.5.16.20</p></div>