Posted 23 Aug 2020 (edited) Hi, this is my first post in Mr.PLC :) In CP1E-N20 I can send c-mode commands to RS232c port to access the memory. The access memory through the USB port is possible? And What is the protocol? I find a project in https://program-plc.blogspot.com/2015/12/omron-plc-usb-protocol-used-for.html to CP1L-L10 When I send to CP1E the "PLC_Run_Mode" = [AB,0,11,80,0,2,0,0,0,0,0,0,69,4,1,FF,FF,4,3,AE], I should get [AB,0,10,C0,0,2,0,0,FB,0,0,0,4,1,0,0] but I receive [AB,0,10,C0,0,2,0,0,0,0,0,0,69,4,1,0,0,1,EB] I need to understand this protocol/message, but I not find information. The Omron W342 does not refer to these messages starts with "0xAB, ..." Someone can help me? Thank you. Jorge Edited 23 Aug 2020 by JorgeTorres change "anyone" to "Someone" Share this post Link to post Share on other sites
Posted 23 Aug 2020 Hi Jorge, The built-in peripheral USB port is for connecting support software only. The protocol is not published. Regards, Garry Share this post Link to post Share on other sites
Posted 23 Aug 2020 Hi @gclshortt, thank you for the reply! I was studying the code of this project and I changed it to read the memory. Now, it works fine with CP1E too :) But I still do not understand some message fields... In the next week, I will test the code with CJ2M, also have the USB port. The serial port is busy and I just have the USB port free to read counters (in DM) Best regards, Jorge Share this post Link to post Share on other sites
Posted 24 Aug 2020 The code of this project also works with CJ2M-CPU34, using the peripheral port (USB). The response of this PLC has some fields different, but the value of memory is in the same position. Jorge Share this post Link to post Share on other sites
Posted 8 Dec 2020 Wow, didn't know someone took the time to trace the USB protocol and create such a project. This is a late reply, but if anything, I recognize the hexadecimal pattern is similar to the Host Link protocol, which is typically used with RS-232 for Omron PLC. IIRC C-mode and Host Link are the same thing as well. If you look on Host Link protocol manual, maybe you can figure things out. Share this post Link to post Share on other sites