https://forge.codesys.com/forge/talk/Engineering/thread/1e154b10ec/2020-02-27T13:53:21.714000ZRecent posts to Modicon reading ABB registers2020-02-27T13:53:21.714000Z2020-02-27T13:53:21.714000ZMRoberthttps://forge.codesys.com/u/mrobert/https://forge.codesys.com7ac69c67587ffe033ae808db1989b6ee6a649017

<div class="markdown_content"><p>One of our Unity PLC's have to read data from an ABB PLC.<br/> The protocol is Modbus TCP-IP.<br/> The addressing methods of the PLCs are different.<br/> I am not sure about :<br/> The byte order inside a word,<br/> The bit order inside a byte and inside a word.<br/> Please look at the examples and confirm or correct.<br/> The ABB word %mw0.100 contains two bytes %mb0.200 and %mb0.201. The byte with the lower address is the Most Significant Byte.<br/> This ABB word %mw0.100 is equivalent to MODICON word 400101.<br/> If this is true so :<br/> The bit %mx0.201.0 is the Least Significant Bit of %mw0.100 and 400101. And the %mx200.15 is the MSB of %mw0.100 and 400101.<br/> I have no access to the ABB code.</p> <p>Please excuse my poor english.</p> <p>Please help,<br/> Robert</p></div>