Kunker Posted July 17, 2020 Report Share Posted July 17, 2020 Hello! I am trying to create a program that will, allow to read Output, Input, Analog statuses and also Enable/Disable Outputs. I have a working program created and it works very well through RS232, however I need to use RS485. My problem is that I can send data through RS485, but i cannot receive. For example by sending the characters through RS485 "OS" the PLC gets the request but replies through RS232 not RS485. P.S. By sending the characters "OS" I should get a reply that displays all the Output Statuses. I have added my program in the attachment. PLC Projekts.U90 Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted July 18, 2020 MVP 2021 Report Share Posted July 18, 2020 A quick look at this and for starters I'd fix all your Input Status Determine inputs......they are all the same......Input 0. As for your comms woes, are you using an MJ20-RS? If not, you should be. It is possible that your 485 sends are being interpreted on the 232 input of an MJ20-PRG, but it cannot send on 485. I suggest you have a good read of the various Help files.....Com Port Mode: RS232/RS485 etc You should initially be just trying out what you want to do on just one I/O, testing this thoroughly until it all works correctly and you understand it completely, then progressively add in other additions you want, testing along the way. cheers, Aus Quote Link to comment Share on other sites More sharing options...
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