Recent posts to Modbus RTU with MAX 485 ?https://forge.codesys.com/forge/talk/Runtime/thread/7d061c507d/2020-02-27T15:55:09.087000ZRecent posts to Modbus RTU with MAX 485 ?Modbus RTU with MAX 485 ?2020-02-27T15:55:09.087000Z2020-02-27T15:55:09.087000Zeschwellingerhttps://forge.codesys.com/u/eschwellinger/https://forge.codesys.com3a112f0f20002a50b4865a3fdb92955556a1196b<div class="markdown_content"><p>Hi Christoph,</p>
<p>maybe this links give more information at least an better explanation:</p>
<p><a class="" href="http://www.raspberrypi.org/forums/viewtopic.php?f=44&t=37203&p=514164&hilit=MAX485#p514164" rel="nofollow">http://www.raspberrypi.org/forums/viewt ... 85#p514164</a><br/>
<a class="" href="https://github.com/mholling/rpirtscts" rel="nofollow">https://github.com/mholling/rpirtscts</a></p>
<p>Regards<br/>
Edwin</p></div>Modbus RTU with MAX 485 ?2020-02-27T15:55:08.292000Z2020-02-27T15:55:08.292000Zeschwellingerhttps://forge.codesys.com/u/eschwellinger/https://forge.codesys.comfed7bbd59e6a3f6b532316e4a192e98eaf2dcb91<div class="markdown_content"><p>Hello Christoph,</p>
<p>I'm not really sure, but using MAX 485 on the tty is not really possible without having <br/>
handshake pins to give the direction. To workaround this by a kind of own implemented mechanism <br/>
will not lead to a reliable solution.<br/>
I would recommend to use a ready to use USB to RS485 Adapter instead implement this with a huge effort.</p>
<p>Maybe I am totally wrong and someone could give us a hint how to solve this with a MAX485 circuit.</p>
<p>Best Regards<br/>
Edwin</p></div>Modbus RTU with MAX 485 ?2020-02-27T15:55:05.999000Z2020-02-27T15:55:05.999000ZKampfwursthttps://forge.codesys.com/u/kampfwurst/https://forge.codesys.com1fb217abf38a95ab92298777a52f54210995ec22<div class="markdown_content"><p>Hello</p>
<p>I have a "big" Problem. <br/>
I would like to use the MAX485 for Modbus RTU on the UART Port (GPIO14 and 15). Everything is fine but for the MAX485 I need to change the direction (transmit or receive) with a pin.<br/>
If this GPIO pin is high i can send through the MAX485. If this GPIO Pin is low than the MAX485 can receive.</p>
<p>Now i have the Problem that can´t get any direction variable from the Modbus library to toggle this Pin so im stuck at the moment.</p>
<p>Has someone maybe any idea</p>
<p>Greetings Christoph</p></div>